The Serbs (Serbian Cyrillic: Срби, romanized: Srbi, pronounced [sr̩̂bi]) are a South Slavic ethnic group native to Southeastern Europe who share a common Serbian ancestry, culture, history, and language. They primarily live in Serbia, Kosovo, Bosnia and Herzegovina, Croatia, Montenegro as well as in North Macedonia, Slovenia, Germany and Austria. They also constitute a significant diaspora with several communities across Europe, the Americas and Oceania.

The Serbs share many cultural traits with the rest of the peoples of Southeast Europe. They are predominantly Eastern Orthodox Christians by religion. The Serbian language (a standardized version of Serbo-Croatian) is official in Serbia, co-official in Kosovo and Bosnia and Herzegovina, and is spoken by the plurality in Montenegro.

The identity of Serbs is rooted in Eastern Orthodoxy and traditions. In the 19th century, the Serbian national identity was manifested, with awareness of history and tradition, medieval heritage, cultural unity, despite living under different empires. Three elements, together with the legacy of the Nemanjić dynasty, were crucial in forging identity and preservation during foreign domination: the Serbian Orthodox Church, the Serbian language, and the Kosovo Myth. When the Principality of Serbia gained independence from the Ottoman Empire, Orthodoxy became crucial in defining the national identity, instead of language which was shared by other South Slavs (Croats and Bosniaks). The tradition of slava, the family saint feast day, is an important ethnic marker of Serb identity, and is usually regarded their most significant and most solemn feast day.

The origin of the ethnonym is unclear. The most prominent theory considers it of Proto-Slavic origin. Hanna Popowska-Taborska argued native Slavic provenance of the ethnonym, claiming that the theory advances a conclusion that the ethnonym has a meaning of a family kinship or alliance, which was also argued by a number of other scholars.

According to a triple analysis – autosomal, mitochondrial and paternal — of available data from large-scale studies on Balto-Slavs and their proximal populations, the whole genome SNP data situates Serbs with Montenegrins in between two Balkan clusters. Y-DNA results show that haplogroups I2a and R1a together stand for the majority of the makeup, with more than 50 percent.

According to several recent studies Serbia's people are among the tallest in the world, with an average male height of 1.82 metres (6 ft 0 in).

Early Slavs, especially Sclaveni and Antae, including the White Serbs, invaded and settled Southeastern Europe in the 6th and 7th century. Up until the late 560s, their activity was raiding, crossing from the Danube, though with limited Slavic settlement mainly through Byzantine foederati colonies. The Danube and Sava frontier was overwhelmed by large-scale Slavic settlement in the late 6th and early 7th century. What is today central Serbia was an important geo-strategical province, through which the Via Militaris crossed. This area was frequently intruded by barbarians in the 5th and 6th centuries. The numerous Slavs mixed with and assimilated the descendants of the indigenous population (Illyrians, Thracians, Dacians, Romans, Celts). White Serbs from White Serbia came to an area near Thessaloniki and then they settled area between Dinaric Alps and Adriatic coast. The region of "Rascia" (Raška) was the center of Serb settlement and Serb tribes also occupied parts of modern-day Herzegovina and Montenegro. Prior to their arrival to the Balkans, early Slavs were predominantly involved in agriculture, which is why they settled in areas which were cultivated even during Roman times.

The first Serb states, Serbia (780–960) and Duklja (825–1120), were formed chiefly under the Vlastimirović and Vojislavljević dynasties respectively. The other Serb-inhabited lands, or principalities, that were mentioned included the "countries" of Paganija, Zahumlje, Travunija. With the decline of the Serbian state of Duklja in the late 11th century, Raška separated from it and replaced it as the most powerful Serbian state. Prince Stefan Nemanja (r. 1169–96) conquered the neighbouring territories of Kosovo, Duklja and Zachlumia. The Nemanjić dynasty ruled over Serbia until the 14th century. Nemanja's older son, Stefan Nemanjić, became Serbia's first recognized king, while his younger son, Rastko, founded the Serbian Orthodox Church in the year 1219, and became known as Saint Sava after his death. Parts of modern-day Montenegro, Bosnia and Herzegovina, and central Serbia would come under the control of Nemanjić.

Over the next 140 years, Serbia expanded its borders, from numerous smaller principalities, reaching to a unified Serbian Empire. Its cultural model remained Byzantine, despite political ambitions directed against the empire. The medieval power and influence of Serbia culminated in the reign of Stefan Dušan, who ruled the state from 1331 until his death in 1355. Ruling as Emperor from 1346, his territory included Macedonia, northern Greece, Montenegro, and almost all of modern Albania. When Dušan died, his son Stephen Uroš V became Emperor.

With Turkish invaders beginning their conquest of the Balkans in the 1350s, a major conflict ensued between them and the Serbs, the first major battle was the Battle of Maritsa (1371), in which the Serbs were defeated. With the death of two important Serb leaders in the battle, and with the death of Stephen Uroš that same year, the Serbian Empire broke up into several small Serbian domains. These states were ruled by feudal lords, with Zeta controlled by the Balšić family, Raška, Kosovo and northern Macedonia held by the Branković family and Lazar Hrebeljanović holding today's Central Serbia and a portion of Kosovo. Hrebeljanović was subsequently accepted as the titular leader of the Serbs because he was married to a member of the Nemanjić dynasty. In 1389, the Serbs faced the Ottomans at the Battle of Kosovo on the plain of Kosovo Polje, near the town of Priština. Both Lazar and Sultan Murad I were killed in the fighting. The battle most likely ended in a stalemate, and afterwards Serbia enjoyed a short period of prosperity under despot Stefan Lazarević and resisted falling to the Turks until 1459.

The Serbs had taken an active part in the wars fought in the Balkans against the Ottoman Empire, and also organized uprisings; because of this, they suffered persecution and their territories were devastated – major migrations from Serbia into Habsburg territory ensued. After allied Christian forces had captured Buda from the Ottoman Empire in 1686 during the Great Turkish War, Serbs from Pannonian Plain (present-day Hungary, Slavonia region in present-day Croatia, Bačka and Banat regions in present-day Serbia) joined the troops of the Habsburg monarchy as separate units known as Serbian Militia. Serbs, as volunteers, massively joined the Austrian side.

Many Serbs were recruited during the devshirme system, a form of slavery in the Ottoman Empire, in which boys from Balkan Christian families were forcibly converted to Islam and trained for infantry units of the Ottoman army known as the Janissaries. A number of Serbs who converted to Islam occupied high-ranking positions within the Ottoman Empire, such as Grand Vizier Sokollu Mehmed Pasha and Minister of War field marshal Omar Pasha Latas.

In 1688, the Habsburg army took Belgrade and entered the territory of present-day Central Serbia. Louis William, Margrave of Baden-Baden called Serbian Patriarch Arsenije III Čarnojević to raise arms against the Turks; the Patriarch accepted and returned to the liberated Peć. As Serbia fell under Habsburg control, Leopold I granted Arsenije nobility and the title of duke. In early November, Arsenije III met with Habsburg commander-in-chief, General Enea Silvio Piccolomini in Prizren; after this talk he sent a note to all Serb bishops to come to him and collaborate only with Habsburg forces.

A Great Migration of the Serbs (1690) to Habsburg lands was undertaken by Patriarch Arsenije III. The large community of Serbs concentrated in Banat, southern Hungary and the Military Frontier included merchants and craftsmen in the cities, but mainly refugees that were peasants. Smaller groups of Serbs also migrated to the Russian Empire, where they occupied high positions in the military circles.

The Serbian Revolution for independence from the Ottoman Empire lasted eleven years, from 1804 until 1815. The revolution comprised two separate uprisings which gained autonomy from the Ottoman Empire that eventually evolved towards full independence (1835–1867). During the First Serbian Uprising, led by Duke Karađorđe Petrović, Serbia was independent for almost a decade before the Ottoman army was able to reoccupy the country. Shortly after this, the Second Serbian Uprising began. Led by Miloš Obrenović, it ended in 1815 with a compromise between Serbian revolutionaries and Ottoman authorities. Likewise, Serbia was one of the first nations in the Balkans to abolish feudalism. Serbs are among the first ethnic groups in Europe to form a nation and a clear sense of national identity.

In the early 1830s, Serbia gained autonomy and its borders were recognized, with Miloš Obrenović being recognized as its ruler. Serbia is the fourth modern-day European country, after France, Austria and the Netherlands, to have a codified legal system, as of 1844. The last Ottoman troops withdrew from Serbia in 1867, although Serbia's and Montenegro's independence was not recognized internationally until the Congress of Berlin in 1878.

Serbia fought in the Balkan Wars of 1912–13, which forced the Ottomans out of the Balkans and doubled the territory and population of the Kingdom of Serbia. In 1914, a young Bosnian Serb student named Gavrilo Princip assassinated Archduke Franz Ferdinand of Austria, which directly contributed to the outbreak of World War I. In the fighting that ensued, Serbia was invaded by Austria-Hungary. Despite being outnumbered, the Serbs defeated the Austro-Hungarians at the Battle of Cer, which marked the first Allied victory over the Central Powers in the war. Further victories at the battles of Kolubara and the Drina meant that Serbia remained unconquered as the war entered its second year. However, an invasion by the forces of Germany, Austria-Hungary and Bulgaria overwhelmed the Serbs in the winter of 1915, and a subsequent withdrawal by the Serbian Army through Albania took the lives of more than 240,000 Serbs. Serb forces spent the remaining years of the war fighting on the Salonika front in Greece, before liberating Serbia from Austro-Hungarian occupation in November 1918. Serbia suffered the biggest casualty rate in World War I.

Following the victory in WWI, Serbs subsequently formed the Kingdom of Serbs, Croats and Slovenes with other South Slavic peoples. The country was later renamed the Kingdom of Yugoslavia, and was led from 1921 to 1934 by King Alexander I of the Serbian Karađorđević dynasty. During World War II, Yugoslavia was invaded by the Axis powers in April 1941. The country was subsequently divided into many pieces, with Serbia being directly occupied by the Germans. Serbs in the Independent State of Croatia (NDH) were targeted for extermination as part of genocide by the Croatian ultra-nationalist, fascist Ustaše. The Ustaše view of national and racial identity, as well as the theory of Serbs as an inferior race, was under the influence of Croatian nationalists and intellectuals from the end of the 19th and the beginning of the 20th century. Jasenovac camp was notorious for the barbaric practices which occurred in it. Sisak and Jastrebarsko concentration camp were specially formed for children. Serbs in the NDH suffered among the highest casualty rates in Europe during the World War II, while the NDH was one of the most lethal regimes in the 20th century. Diana Budisavljević, a humanitarian of Austrian descent, carried out rescue operations from Ustaše camps and saved more than 15,000 children, mostly Serbs.

More than half a million Serbs were killed in the territory of Yugoslavia during World War II. Serbs in occupied Yugoslavia subsequently formed a resistance movement known as the Yugoslav Army in the Homeland, or the Chetniks. The Chetniks had the official support of the Allies until 1943, when Allied support shifted to the Communist Yugoslav Partisans, a multi-ethnic force, formed in 1941, which also had a large majority of Serbs in its ranks in the first two years of war. Over the entirety of the war, the ethnic composition of the Partisans was 53 percent Serb. During the entire course of the WWII in Yugoslavia, 64.1% of all Bosnian Partisans were Serbs. Later, after the fall of Italy in September 1943, other ethnic groups joined Partisans in larger numbers.

At the end of the war, the Partisans, led by Josip Broz Tito, emerged victorious. Yugoslavia subsequently became a Communist state. Tito died in 1980, and his death saw Yugoslavia plunge into economic turmoil. Yugoslavia disintegrated in the early 1990s, and a series of wars resulted in the creation of five new states. The heaviest fighting occurred in Croatia, Bosnia and Herzegovina, whose Serb populations rebelled and declared independence. The war in Croatia ended in August 1995, with a Croatian military offensive known as Operation Storm put a stop to the Croatian Serb rebellion and causing as many as 200,000 Serbs to flee the country. The Bosnian War ended that same year, with the Dayton Agreement dividing the country along ethnic lines. In 1998–99, a conflict in Kosovo between the Yugoslav Army and Albanians seeking independence erupted into full-out war, resulting in a 78-day-long NATO bombing campaign which effectively drove Yugoslav security forces from Kosovo. Subsequently, more than 200,000 Serbs and other non-Albanians fled the province. On 5 October 2000, Yugoslav President Slobodan Milosević was overthrown in a bloodless revolt after he refused to admit defeat in the 2000 Yugoslav general election.

Modern demographic distribution of ethnic Serbs throughout homeland and native regions, as well as in Serbian ethnic diaspora, represents an outcome of several historical and demographic processes, shaped both by economic migrations and forced displacements during the recent Yugoslav Wars (1991–1999).

According to most recent census conducted in Serbia, Croatia and Montenegro, there are nearly 7 million Serbs living in their native homelands, within the geographical borders of former Yugoslavia. In Serbia itself, around 5.5 million people identify themselves as ethnic Serbs, and constitute about 83% of the population. More than a million live in Bosnia and Herzegovina (predominantly in the Republika Srpska), where they are one of the three constituent ethnic groups. Serbs in Croatia, Montenegro and North Macedonia also have recognized collective rights, and number some 186,000, 178,000 and 39,000 people, respectively, while another estimated 96,000 live in the disputed area of Kosovo. Smaller minorities exist in Slovenia, some 36,000 people, respectively.

Outside of the former Yugoslavia, but within their historical and migratory areal, Serbs are officially recognized as national minority in Albania, Romania (18,000), Hungary (7,000), as well as in the Czech Republic and Slovakia.