Quezon, officially the Province of Quezon (Filipino: Lalawigan ng Quezon) and historically known as Tayabas, is a province in the Philippines located in the Calabarzon region on Luzon. Lucena, a highly urbanized city governed separately from the province, serves as its the provincial capital and its most populous city. The name of the province came from Manuel L. Quezon, the president of the Philippines from 1935 to 1944. The province was known as Kalilayan upon its creation in 1591, renamed as Tayabas by the 18th century, before settling on its current name in 1946. To distinguish the province from Quezon City, it is also known as Quezon Province, a variation of the province's official name.

One of the largest provinces in the country, Quezon is situated on the southeastern portion of Luzon, with the majority of its territory lying on an isthmus that connects the Bicol Peninsula to the rest of Luzon. It also includes the Polillo Islands in the eastern part of the province. It is bordered by the provinces of Aurora and Bulacan to the north, Rizal, Laguna, and Batangas to the west, and Camarines Norte and Camarines Sur to the southeast. It also shares maritime borders with Marinduque and Masbate.

Archaeological excavations in the province attest to its rich precolonial past. Archaeological materials including burial jars, human bones, shell midden and pot shreds have been discovered at different sites in Bondoc Peninsula including the towns of San Narciso, San Andres, Mulanay and Catanauan. The most recent excavations were conducted in Catanauan by the Catanauan Archeological and Heritage Project.

According to the preliminary report released by the Catanauan Archaeological and Heritage Project, several excavations were conducted in the 1930s. One of the excavations was conducted in San Narciso where archaeologists found burial jars. The site, inspected by Ricardo Galang, resulted in the discovery of burial jars near the coast. Galang also went to San Andres where excavations yielded 14th and 15th century ceramics as well as shell bracelets and beads. According to the journal as well, at a site named Tala, archaeologists discovered a glazed Chinese jar containing bone fragments from the early Ming dynasty. Looking at other archaeological sites located in adjacent areas like Marinduque and Masbate, it can be inferred that these excavations date back to the metal period of the archipelago.

In 2012, at Mt. Kamhantik in the town of Mulanay, 15 limestone coffins were discovered. Carbon dating on a human tooth found it to be at least 1,000 years old. According to the archaeologists, the village is proof that the ancient inhabitants of the area practiced a more sophisticated way of life. Metal tools are believed to have been used to carve the coffins, and this is the first of its kind discovered in the archipelago. The remains are said to date back to the 10th to 14th century.

Originally, what now forms Quezon was divided among the provinces of Batangas, Laguna, and Nueva Ecija. However, at different points in time, the boundaries of Quezon changed and included parts of Aurora, Marinduque, and Camarines Norte. At the early period of Spanish colonization, the province of Aurora was called El Principe, Infanta was called Binangonan de Lampon, and southern Quezon was called Kalilayan. The first European to explore the area was Juan de Salcedo in 1571–1572, during his expedition from Laguna to Camarines provinces.

In 1574, Father Diego de Oropesa founded the town of Bumaka, now known as the municipality of Gumaca.

In 1591, through Governor General Gómez Pérez Dasmariñas, the province was created and was called Kaliraya or Kalilayan, after the capital town which later became Unisan.

In 1595, the Diocese of Cáceres was established by Pope Clement VIII as a suffragan of Manila. The diocese covered the entire Bicolandia region plus the towns in Kalilayan, and the Contracosta towns. At that time, the towns on the eastern seaboard were pertained to as the Contracosta and included towns from Mauban, Binangonan de Lampon, to El Principe.

The destruction of Kalilayan in 1604 by a big fleet of Moro pirates caused the inhabitants to transfer to Palsabangon (Pagbilao). Depredation and plunder by the Moros from Jolo and Brunei were rampant during the 1600s. Slavery is one reason for the proliferation of these raids. A padron for Calilaya was ordered after Tayabas suffered severely from Moro raids. It is said that 187 people were either captured or killed while 400 people fled. Fear from these raids are the primary reason as to the permanent movement of settlements along the coast further inland as well as a general decline in population. Frequent invasions by the moros disrupted the food production in the province, affecting the nutrition of its inhabitants. Maternal malnutrition was even cited as one of the primary causes of infant mortality at that time. By 1701, the previously densely settled coastal areas of the province, was described as consisting of rancherias whose inhabitants depended on wild products.

In 1705, the Military Comandancia of Nueva Ecija was created and was governed by Governor General Fausto Cruzat y Góngora. It included huge swathes of Central Luzon, the Contracosta towns as well as the Kalilayan area and Polillo Islands. But Nueva Ecija was still part of La Pampanga province at that time. Since Contracosta & Kalilayan were part of La Laguna province at that time before including them in Nueva Ecija, they became jointly ruled by La Pampanga & La Laguna provinces.

In 1749, the capital was transferred to the town of Tayabas, from which the province got its new name.

In a report by a Spanish priest named Fr. Bartolome Galan in 1823, he describes the economy of the province. According to his report, Tayabas had poor soil and the terrain is hilly which meant that conditions were not that suitable for agriculture compared to other places. The people grew upland rice, wheat, beans and vegetables. Surplus rice was sold in San Pablo and Majayjay on Mondays, the market day of those towns. Cattle breeding was rampant in towns like Tayabas, Pagbilao, Tiaong, and Sariaya. Also, unlike other provinces, haciendas were not so many in Tayabas. Instead, residents owned most of their own land.

The people of Tayabas, as in other areas, are actively trading with Manila. Santa Cruz, Laguna, was the entrepot for all goods going to the capital. The people from Lucban made products of buri and pandan leaves like hats, sleeping mata and the like which they traded. They, along with the people of Mauban also went to Polillo, at that time part of Nueva Ecija, to buy sea slugs, shells and beeswax. Being a rich agricultural area, the town of Tayabas traded rice, coconuts, and panocha with nearby towns of Majayjay, Lucban, Sariaya, Pagbilao, Mauban, Gumaca, and Atimonan. In turn, they traded fish from Pagbilao, rice from Sariaya, and high quality abaca products from Mauban and Atimonan. Lucban, as well as Tayabas, benefitted greatly from the high commercial activity of Chinese and Chinese mestizos in the pueblos.

Gumaca, being a town with little arable land depended heavily on the sea. They collected sea slugs, and tortoise shell from Alabat and traded with the mountain people there for beeswax in exchange for clothing. They even sometimes ventured to Burias Island in Ragay Gulf in search for these goods. These products were then sent to Tayabas for shipment to Manila. Gumaca also traded items from nearby pueblos like vinegar and clothing for gold and abaca from Naga in the Bicol region.

In 1818, Nueva Ecija annexed the towns of Palanan from Isabela, as well as Baler, Casiguran, Infanta (formerly called Binangonan de Lampon) and Polillo Islands from Tayabas, and Cagayan, Nueva Vizcaya, Quirino, and part of Rizal.

In 1853, the new military district of Tayabas was carved from Nueva Ecija and included present-day Southern Quezon as well as present-day Aurora. In 1858, Binangonan de Lampon and the Polillo Islands were separated from Nueva Ecija to form part of Infanta. According to the Catholic Bishops' Conference of the Philippines, the two Franciscan friars named Fray Juan de Plasencia and Fray Diego de Oropesa were the ones responsible for bringing Christianity to the area. The Franciscans are also credited for spreading Christianity to towns and parishes across the province including Mauban, Sariaya and Gumaca.

Between 1855 and 1885, El Principe was established as its own Military Comandancia with its capital in Baler.

It was also around this time that the Confradia de San Jose was active in the province, caused by the growing inequality between the poor and the upper classes. This organization was directed mostly on the poor and neither admitted Spaniards nor mestizos.

After years under the Spanish regime, the colonized people grew discontented with the Spaniards over the centuries. The most important event in the history of the province was the Confradia Revolt in 1841, which was led by the famous Lucbanin, Apolinario de la Cruz, popularly known as Hermano Pule.

Years after the Cofradia Revolt, on January 20, 1843, the Tayabas Regiment, led by Sergeant Irineo Samaniego, rose in revolt against Spain, conquering Fort Santiago and other areas of Intramuros. This is the only native force in Philippine history to successfully capture Fort Santiago and Manila. For the first time, the word "Independence" was shouted by the Tayabas Regiment, encouraging their countrymen to revolt against Spain. The next day, however, the gates of Fort Santiago were opened by loyalist soldiers. After a bloody battle, the mutineers were defeated by loyalist troops, resulting in the execution of Samaniego and 81 of his followers the same day.

The province, under General Miguel Malvar, was also among the earliest to join the Philippine Revolution. The Revolutionary Government took control over the province on August 15, 1898.

The Americans then came and annexed the Philippines. A civil government was established in the province on March 12, 1901, and Lucena was made the provincial capital.

During the pacification of the archipelago by the Americans, insurrections were a commonplace in what was then Tayabas. Insurgents from neighboring provinces of Laguna and Batangas often use Tayabas as their base of operations as well as their source of supplies. An insurgent government, with connections to Gen. Malvar and Pedro Caballes was even said to be based in Infanta. This has led the American in charge, Brigadier-General J.F. Bell to decide to return to Tayabas with a larger contingent. Bell acknowledged the importance of the ports of Tayabas as sources of supplies to the insurrection such that he believed that closing all the ports in the province might convince the leaders of the resistance to surrender.

In 1902, the district of El Principe was transferred from the jurisdiction of Nueva Ecija to Tayabas. In the same year, Marinduque became part of Tayabas province by virtue of Act 499 enacted by the Philippine Commission. However, by 1920, Act 2280 was passed by the Philippine Congress, reestablishing Marinduque as a separate province. The present areas of north Aurora which is part of the modern Dilasag and area of modern Casiguran were transferred from the authority of Nueva Vizcaya to Tayabas in 1905. In 1918, the area of modern Aurora north of Baler was transferred to the authority of Nueva Vizcaya, but returned to Tayabas in 1946.

Because of the distance between Tayabas and Bicol and the growing population, Tayabas came under the jurisdiction of the Diocese of Lipa in 1910.

Japanese occupation of the province during World War II began on December 23, 1941, when the Japanese Imperial Army landed in Atimonan. The General Headquarters of the Philippine Commonwealth Army and Philippine Constabulary was stationed in Tayabas from January 3, 1942, to June 30, 1946, are military operates against the Japanese Occupation. The occupation witnessed the brutal murders of prominent sons of Tayabas. April 4, 1945 was the day the province was liberated as the combined Filipino and American army forces reached Lucena.

After the war, on September 7, 1946, Republic Act No. 14 changed the name Tayabas to Quezon, in honor of Manuel L. Quezon, the Commonwealth president who hailed from Baler, which was one of the province's towns; he was elected governor of Tayabas in 1906 and congressman of 1st district of Tayabas in 1907. The name is Chinese mestizo surname originally from a Spanish-era romanization of Hokkien Chinese, possibly from the Hokkien word, Chinese: 雞孫; Pe̍h-ōe-jī: ke-sun / koe-sun, with Chinese: 雞; Pe̍h-ōe-jī: ke meaning "outer city" or "strongest" and Chinese: 孫; Pe̍h-ōe-jī: sun meaning "grandson"; many Filipino surnames that end with “on”, “son”, and “zon” are of Chinese origin, Hispanized version of 孫 (sun); his father is a descendant of Chinese settlers.

Even before the Philippines gained its independence, the province has already depended heavily on coconuts. This history can clearly be seen through the opulent houses built in the town of Sariaya during this period. Coconuts served as the main source of income for the landed class of Sariaya and this allowed them to build the ancestral houses that we see today. This has led some companies like Peter Paul to establish its presence in Candelaria to manufacture products like desiccated coconut. as early as this period.

In June 1951, the northern part of Quezon (specifically, the towns of Baler, Casiguran, Dilasag, Dingalan, Dinalongan, Dipaculao, Maria Aurora and San Luis) was made into the sub-province of Aurora. Aurora was the name of the president's wife, Aurora Quezon, who was also born and grew up in Baler. Aurora was finally separated from Quezon as an independent province in 1979. One obvious reason for creating Aurora is due to the area's isolation from the rest of Quezon Province: there are no direct links to the rest of the province and much of the terrain is mountainous and heavily forested, which makes the area relatively isolated, and its distance from Quezon's capital Lucena. Upon the issuance of Executive Order No. 103, dated May 17, 2002, by then-President Gloria Macapagal Arroyo, the province of Aurora was moved to Central Luzon (Region III), geographical location of the province; the remaining areas of Quezon & other provinces of Southern Tagalog divided into Calabarzon and Mimaropa, and Southern Tagalog was limited to being a cultural-geographic region. The total separation of Aurora from Quezon & transfer of Aurora to Central Luzon were the fulfillment of the wishes and prayers of the residents of the original Municipalities of Baler and Casiguran to be truly independent from Quezon Province for the first time & to reform the original La Pampanga since the Spanish occupation.

Quezon Province was not spared the social and economic turmoil during the Dictatorship of Ferdinand Marcos, including his 1971 suspension of the writ of habeas corpus, his 1972 declaration of martial law, and his continued hold on power from the lifting of martial law in 1981 until his ouster under the People Power Revolution of 1986. One major event that took place during this period was the Guinayangan massacre of February 1, 1981, in which Military elements opened fire on a group of about coconut farmers who were marching towards the Guinayangan plaza air to protest the coco levy fund scam. Two people were killed and 27 were wounded.

Among the Quezon citizens who were victims of forced disappearances during the Marcos dictatorship were human rights worker Albert Enriquez of Lucena, who documented military abuses as a volunteer for Task Force Detainees of the Philippines; and activist Ramon Jasul who founded the Bagong Kabataan ng Lukban (New Youth of Lucban) in his hometown. Enriquez was abducted by armed men on Aug. 29, 1985, while Jasul was abducted in Makati as part of the Southern Tagalog 10 incident of late July 1977. Neither were ever seen again, and both were eventually honored by having their names engraved on the wall of remembrance at the Philippines' Bantayog ng mga Bayani.

In 1989, the province of Quezon, represented by Governor Hjalmar Quintana, was involved in a boundary dispute with the province of Camarines Norte, represented by Roy Padilla, over 9 barangays of over 8,000 hectares (20,000 acres) at their border. These barangays are Kagtalaba, Plaridel, Kabuluan, Don Tomas, Guitol, Tabugon, Maualawin, Patag Ibaba and Patag Iraya. The boundary dispute originated from Act 2711 or the Revised Administrative Code which was enacted in 1917. Section 42 of Act 2711 defines the Tayabas-Camarines Norte boundary as:

Camarines Norte and Tayabas boundary. – The boundary separating the Province of Camarines Norte from the Province of Tayabas begins at a point on the eastern shore of Basiad Bay and extends to a peak known as Mount Cadig in such manner as to bring the territory of the barrio of Basiad entirely within the municipality of Capalonga, in Camarines Norte, and to exclude the same from the territory of Calauag, in Tayabas. From Mount Cadig it extends along the crest of a mountain range, a distance of 50 kilometers, more or less, to a peak known as Mount Labo; thence in a southwesterly direction, a distance of 25 kilometers, more or less, to a prominent stone monument at the source or headwaters of the Pasay River, thence along the meandering course of said river in a southerly direction, a distance of 1½ kilometers, more or less, to the Gulf of Ragay.

In 1922, the then chief of the Executive Bureau, acted upon the authority of the secretary of the interior. This ruling by the then chief was never implemented even with repeated efforts of the provincial government of Camarines Norte and the secretary of the interior. The chief delineated the border as follows:

Starting from the peak of Mt. Labo as a common corner between the provinces of Tayabas, Camarines Sur and Camarines Norte thence a straight line is drawn to the peak of Mt. Cadig; thence a straight line is drawn to the point of intersection of the inter-provincial road between Camarines Norte and Tayabas with the Tabugon River; thence, following the course of the river to its mouth at Basiad Bay.

In the legal dispute, Quezon raised two points of contention. First is that Act 2711 already delineated the boundaries of the province. Second is that the Chief of the Executive Bureau had no power nor authority to change the boundaries of the province. Regarding the first issue, the court stated that it is true that Act 2711 delineated the boundary but it did not delineate the entirety of the boundary. The point on the eastern shore of Basiad Bay was never specifically located, thus, needing further delineation. On the second issue, the court stated that the Chief did not alter the borders in any way. The Chief worked with the requirement that the point be on the eastern shore of Basiad Bay. He was also acting on the consideration of Act 2809, the Act establishing Camarines Norte, which states that Camarines Norte be established with the borders it had before merging with Camarines Sur. The court then ruled in favor of Camarines Norte and ordered the provincial government of Quezon to transfer all its authority and jurisdiction to the former.

By 2001, the Provincial Government of Quezon, this time represented by Governor Eduardo Rodriguez, the Provincial Government of Camarines Norte, as represented by Governor Roy Padilla, went back to court. Even with the judgment on the 1989 case was executory by 1990, the provincial government of Quezon did not abide by the court's ruling. In 1991, a Department of Environment and Natural Resources (DENR) technical team conducted a survey of the area and erected a monument marker to delineate the boundary of the area. However, by October 1991, Quezon Governor Eduardo Rodriguez and Calauag Mayor Julio Lim caused the removal of the marker. Throughout the proceedings, several government agencies including the Department of Budget and Management, Comelec, as well as the Philippine Statistics Authority recognized the jurisdiction of the town of Santa Elena, Camarines Norte over the 9 barangays. In 2000, Judge Regino held Governor Rodriguez and Mayor Lim guilty of contempt, with a maximum imprisonment of 6 months as well as a fine of ₱1,000 for the erection of a new boundary marker.

In 2007, Republic Act No. 9495 proposed to further divide Quezon into Quezon del Norte and Quezon del Sur. Quezon del Norte was to be composed of the first and second congressional districts of the province (Burdeos, General Nakar, Infanta, Jomalig, Lucban, Mauban, Pagbilao, Panukulan, Patnanungan, Polilio, Real, Sampaloc, Tayabas, Candelaria, Dolores, San Antonio, Sariaya, Tiaong and Lucena), with Lucena as its capital. Quezon del Sur, with its capital at Gumaca, would have been composed of the third and fourth congressional districts (Agdangan, Buenavista, Catanauan, General Luna, Macalelon, Mulanay, Padre Burgos, Pitogo, San Andres, San Francisco, San Narciso, Unisan, Alabat, Atimonan, Calauag, Guinayangan, Gumaca, Lopez, Perez, Plaridel, Quezon and Tagkawayan). The act lapsed into law without the signature of President Gloria Macapagal Arroyo on September 7, 2007.

As required by law, the COMELEC held a plebiscite on December 13, 2008, 60 days after law took effect. The majority of the votes cast overwhelmingly rejected the division, therefore the split did not push through.

The municipality of Tayabas became a component city by virtue of Republic Act No. 9398 which sought to convert the municipality into a city. The law was ratified on July 14, 2007. However, the cityhood status was lost twice in the years 2008 and 2010 after the LCP questioned the validity of the cityhood law. The cityhood status was reaffirmed after the court finalized its ruling on February 15, 2011 which declared the cityhood law constitutional.

Quezon, east of Metro Manila, is the 8th largest province in the Philippines having an area of 8,989.39 square kilometers (3,470.82 sq mi). It is the largest province of Calabarzon, comprising 879,660 hectares (2,173,700 acres) or 52.13% of the total land area of the region. Of this area, 513,618 hectares (1,269,180 acres) is categorized as agricultural land. The northern part of the province is sandwiched between the Sierra Madre mountain range and the Philippine Sea. The southern part consists of the Tayabas Isthmus, which separates the Bicol Peninsula from the main part of Luzon Island, and the Bondoc Peninsula which lies between Tayabas Bay and Ragay Gulf. Because of this, majority of towns in the province have access to the sea. The province is bounded by the provinces of Aurora, Bulacan, Rizal, Laguna, Batangas, Camarines Sur and Camarines Norte. It is bounded to the east by the Pacific Ocean and to the south by Tayabas Bay. The province is said to be characterized by a rugged terrain with patches of plains, valleys and swamps.

The major islands of Quezon are Alabat Island and Polillo Islands. Mount Banahaw, an active volcano, is the highest peak at 2,169 meters (7,116 ft). It supplies geothermal power to the Mak-Ban Geothermal Power Plant.

The province has a total of 1,066.36 km (662.61 mi) of coastline and has several bays including Burdeos Bay, Lamon Bay, Calauag Bay, Lopez Bay, Ragay Gulf, Pagbilao Bay and Tayabas Bay. The Infanta Watershed has extensive and highly productive aquifers while Mauban and Atimonan have no significant groundwater. According to the DENR, in 2003, Quezon had 231,190 hectares (571,300 acres) of forest cover. However, due to rampant illegal logging as well as kaingin, these forests are constantly threatened.

Because of the sheer size of Quezon, different areas have different climate patterns. Most of the province falls under Type IV Climate which means that rains are evenly distributed throughout the year. Polillo, Infanta, and parts of Calauag fall under Type II climate which means that there are no dry seasons but there is a pronounced wet season from November to April. Parts of the western towns of Tiaong, San Antonio, Dolores, and Candelaria as well as the tip of Bondoc Peninsula including parts of Mulanay, San Francisco, San Narciso and San Andres fall under Type III climate. This means that there is a relatively dry season from November to April. Although these are the patterns observed, it is important to note that with climate change, these patterns have become more erratic. Typhoons have become stronger through the years, causing problems such as power outages, road blockages, landslides, flashfloods and crop damages.

Administrative divisions and population of Tayabas in 1800s

Town	Tributes	Inhabitants
Tayabas	4,283.5	21,418
Lucban	2,829.5	14,147
Saryaya	1,722.5	8,614
Tiaon	692	3,460
Dolores	450	2,250
Mauban	1,323	6,615
Atimonan	1,176	5,880
Gumaca	1,848	9,240
Pagbilao	496	2,480
Pitogo	276	1,380
Macalelon	155	775
Catanauan	450	2,250
Mulanay	305	1,525
Obuyon	265	1,325
Calauag	63	315
Apad	63	315
Guinyangan	212	1,060
Total		83,049

In 1902, during the American period, Tayabas was divided as follows:

Administrative divisions and population of Tayabas in 1902

Town	Population
Alabat	4,516
Atimonan	11,203
Baler	2,417
Bondoc	1,330
Calauag	3,185
Casiguran	2,067
Catanauan	4,108
Guinayangan	3,870
Gumaca	5,234
Infanta	10,283
Lopez	8,549
Lucban	10,227
Lucena	9,375
Macalelon	4,759
Mauban	12,021
Mulanay	2,149
Pagbilao	6,085
Pitogo	3,454
Polillo	2,164
Sampaloc	1,263
San Narciso	2,501
Sariaya	12,453
Tayabas	14,740
Tiaong	9,527
Unisan	2,692
Total	150,262

Population census of Quezon

Year Pop. ±% p.a. 1903 148,581 —     1918 206,037 +2.20% 1939 340,273 +2.42% 1948 393,894 +1.64% 1960 610,599 +3.72%	Year Pop. ±% p.a. 1970 825,859 +3.06% 1975 933,566 +2.49% 1980 1,021,397 +1.81% 1990 1,221,831 +1.81% 1995 1,359,992 +2.03%	Year Pop. ±% p.a. 2000 1,482,955 +1.87% 2007 1,646,510 +1.45% 2010 1,740,638 +2.04% 2015 1,856,582 +1.24% 2020 1,950,459 +0.97%
(excluding Lucena) Source: Philippine Statistics Authority

When the Census of the Philippine Islands was conducted in 1902 during the American era, Tayabas, excluding the subprovince of Marinduque, had a total population of 153,065. 2,803 were considered as wild, or part of the non-Christian tribes such as the Aetas while 150,262 people were considered as civilized. Of the civilized population, 75,774 were males while 74,488 were female. 287 were of mixed descent while the rest are categorized as "Brown".

Based on 2010 census of the household population in Quezon, 90.0 percent reported Tagalog as their ethnicity. The other 10.0 percent were reported as belonging to these ethnic groups: Bisaya/Binisaya (4.2 percent), Bikol/Bicol (3.6 percent), Cebuano (0.6 percent), Ilocano (0.2 percent), and others.

The population of Quezon in the 2020 census was 1,950,459 people, with a density of 220 inhabitants per square kilometre or 570 inhabitants per square mile. When Lucena City is included for geographical purposes, the province's population is 2,229,383 people, with a density of 234/km (606/sq mi).

The inhabitants are mostly Tagalogs. The population is concentrated in the flat south-central portion which includes Lucena City, Sariaya, and Candelaria. After World War II, Infanta and surrounding towns received migrants from Manila, Laguna, Rizal and Batangas. People from Marinduque and Romblon moved to the southern part of the Tayabas Isthmus and northern parts of the Bondoc Peninsula. Visayans from Panay, Negros, Cebu, Bohol, Siquijor, Eastern Visayas and Masbate moved to the southernmost towns of Bondoc Peninsula, particularly in San Francisco and San Andres (people from Romblon are also Visayans). Ilocanos from Ilocos Region, Cagayan Valley, Central Luzon and Cordillera Administrative Region migrated to the northernmost towns of General Nakar, Infanta and Real, and even to Tagkawayan. Bicolanos from Bicol Region migrated to the easternmost towns of Calauag and Tagkawayan.

Filipino Chinese also have a long history in Tayabas (modern Quezon, Aurora and Marinduque provinces). In 1939, the province ranked 5th among all provinces including Manila in terms of the concentration of Filipino Chinese. This ethnic group has a long history of being active in business and commerce as shown by the business chambers existent before. However, as the Chinese intermarried with locals, these groups have dwindled in number.

Population of Filipino Chinese

Province	1903	1918	1939
Tayabas	479	1,274	4,069

The province used to be home to various Aeta tribes. Other terms used to call them include "Umag", "Ata", "Atid", and "Itim". The Aeta used to clear coconut plantations and other odd jobs in exchange for food or clothing. These people, though seem as uncivilized by some, have a very rich culture. Some forms of their art include body scarification. The Aeta cause wound on their skin in various parts of their body including back, arms, legs, hands, calves and abdomen. They then irritate them during healing using fire, lime and other materials to form scars. They also bore holes on their septum and then proceed to decorate it with a sliver of bamboo. The Aeta also have various musical instruments like the nose flute and the gurimbaw, a stringed instrument made of coconuts, fibers from lukmong vines and bamboo.

There are six indigenous languages in Quezon Province: the dominant Tagalog language, the Hatang Kayi language in the north, the Manide language in the east and a small portion in the north, the Umiray Dumaget language in the north and a small area in the center, the already-extinct Katabangan language, which used to be in the south, and the Inagta Alabat language on Alabat Island, which is classified as Critically Endangered, meaning the youngest speakers are grandparents and older and they speak the language partially and infrequently and hardly pass it on to their children and grandchildren anymore.

The province primarily speaks a Tagalog dialect called Tayabas Tagalog or Tayabasin. Tayabas Tagalog has the cultural dynamics of linangin and bayanin. With that, deeper Tagalog is also classified as amot or linangin, which, in the Tayabas context, is related to something remote or far from the bayan or town center. Most of the Tayabas dialectal terms are not found in the Filipino dictionary, or if they are, they have a different meaning. Within the province, there are also variants of dialectal terms that may be peculiar to other towns. Aside from some influences from Chinese, Spanish, and English, which are similar to standardized Tagalog, Tayabasin has influences from the Bicol Region, Marinduque, Batangas, Laguna, and even the Ilocos and Visayas. The dialect is also known for distinctive expressions like hane, kawasa, ngani baya, mandin, and yano. Tayabas Tagalog is also divided into two dialects: the western dialect, which is closer to Batangueño, and the eastern dialect, which is closer to Marinduqueño. Other major languages spoken in Quezon are Ilocano, Visayan languages, and Bikol languages, spoken by descendants of migrants mentioned above.

Majority of Quezon's inhabitants primarily practice Roman Catholicism, which is overwhelmingly accounts to 91.7% or more than nine out of ten of the entire population of the province, while the City of Lucena accounts to 91.3% of the city population. Quezon contributes to Catholic population as the sixteenth most Catholic province in the Philippines, with 1.9 million faithfuls, whilst the City of Lucena is the seventh most Catholic highly urbanized city in the Philippines, with more than 254,000 faithfuls. Catholic hierarchy in the province is subdivided by two Dioceses of Lucena, and Gumaca with the latter born out of the former in 1984 and Catholic Prelate of Infanta was established on 25 April 1950, a month after Lucena Diocese was established. The prelature of Infanta is shared with Aurora, being a former part and forerunner of Quezon. Among other Christian denominations like Philippine Independent Church, Iglesia ni Cristo shares a smaller size of the percentage. Most non-Christians practice Islam, Indigenous Philippine folk religions, animism, or atheism.