Molokai (/ˌmoʊloʊˈkaɪ/) (Hawaiian: Molokaʻi pronounced [ˈmoloˈkɐi, ˈmoloˈkɐʔi]) is the fifth most populated of the eight major islands that make up the Hawaiian Islands archipelago in the middle of the Pacific Ocean. It is 38 by 10 miles (61 by 16 km) at its greatest length and width with a usable land area of 260 sq mi (673.40 km), making it the fifth-largest in size of the main Hawaiian Islands and the 27th largest island in the United States. It lies southeast of Oʻahu across the 25 mi (40 km) wide Kaʻiwi Channel and north of Lānaʻi, separated from it by the Kalohi Channel.

The island's agrarian economy has been driven primarily by cattle ranching, pineapple production, sugarcane production and small-scale farming. Tourism comprises a small fraction of the island's economy, and much of the infrastructure related to tourism was closed and barricaded in the early 2000s when the primary landowner, Molokai Ranch, ceased operations due to substantial revenue losses. In Kalawao County, on the Kalaupapa Peninsula on the north coast, settlements were established in 1866 for quarantined treatment of persons with leprosy; these operated until 1969. The Kalaupapa National Historical Park now preserves this entire county and area. Several other islands are visible from the shores of Molokai, including Oahu from the west shores; Lanai from the south shores, and Maui from the south and east shores.

The island is known under several names by the local population: Molokaʻi ʻĀina Momona (land of abundance), Molokaʻi Pule Oʻo (powerful prayer), and Molokaʻi Nui A Hina (of the goddess Hina).

Both the form Molokai (without an ʻokina) and Molokaʻi (with) have long been used by native speakers of Hawaiian, and there is debate as to which is the original form, with conflicting claims as to which the elders used. The USGS uses the form with the ʻokina.

Molokai developed from two distinct shield volcanoes known as East Molokai and the much smaller West Molokai. The highest point is Kamakou on East Molokai, at 4,970 ft (1,510 m). Today, East Molokai volcano, like the Koʻolau Range on Oʻahu, is what remains of the southern half of the original mountain. The northern half suffered a catastrophic collapse about 1.5 million years ago and now lies as a debris field scattered northward across the bottom of the Pacific Ocean. What remains of the volcano on the island include the highest sea cliffs in the world. The south shore of Molokai boasts the longest fringing reef in the U.S. and its holdings—nearly 25 mi (40 km) long.

Molokai is part of the state of Hawaii and located in Maui County, Hawaii, except for the Kalaupapa Peninsula, which is separately administered as Kalawao County. Maui County encompasses Maui, Lanai, and Kahoolawe in addition to Molokai. The largest town on the island is Kaunakakai, which is one of two small ports on the island. Molokai Airport is located on the central plains of Molokai.

The United States Census Bureau divides the island into three census tracts, Census Tract 317 and Census Tract 318 of Maui County and Census Tract 319 of Kalawao County. The total 2010 census population of these was 7,345, living on a land area of 260.02 sq mi (673.45 km). Molokai is separated from Oahu to the northwest by the Molokai Channel, from Maui to the southeast by the Pailolo Channel and from Lanai to the south by the Kalohi Channel.

The Kauhako Crater Lake is a soda lake.

Molokai is split into two main geographical areas. The low western half is very dry and the soil is heavily denuded due to poor land management practices, which allowed over-grazing by deer and goats. It lacks significant ground cover and virtually the entire section is covered in non-native kiawe (Prosopis pallida) trees. One of the few natural areas remaining almost intact are the coastal dunes of Moʻomomi, which are part of a Nature Conservancy preserve.

The eastern half of the island is a high plateau rising up to an elevation of 4,900 ft (1,500 m) on Kamakou peak and includes the 2,774 acres (11.23 km; 4.334 sq mi) Molokai Forest Reserve. The eastern half is covered with lush wet forests that get more than 300 in (7,600 mm) of rain per year. The high-elevation forests are populated by native ʻōhiʻa lehua (Metrosideros polymorpha) trees and an extremely diverse endemic flora and fauna in the understory. Much of the summit area is protected by the Nature Conservancy's Kamakou and Pelekunu valley preserves.

Below 4,000 ft (1,200 m), the vegetation is dominated by introduced and invasive flora, including strawberry guava (Psidium littorale), eucalyptus (Eucalyptus spp.), and cypress (Cupressus spp.). Introduced axis deer (Axis axis) and feral pigs (Sus scrofa) roam native forests, destroying native plants, expanding spreading invasive plants through disturbance and distribution of their seeds, and threatening endemic insects. Near the summit of Kamakou is the unique Pēpēʻōpae bog, where dwarf ʻōhiʻa and other plants cover the soggy ground.

Molokai is home to a great number of endemic plant and animal species. However, many of its species, including the olomaʻo (Myadestes lanaiensis), kākāwahie (Paroreomyza flammea), and the Bishop's ‘ō‘ō (Moho bishopi) have become extinct. Molokai is home to a wingless fly among many other endemic insects.

It used to be thought that Molokai was first settled around AD 650 by indigenous peoples most likely from the Marquesas Islands. However, a 2010 study using revised, high-precision radiocarbon dating based on more reliable samples has established that the period of eastern Polynesian colonization of the Marquesas Islands took place much later, in a shorter time frame of two waves: the "earliest in the Society Islands c. 1025–1120, four centuries later than previously assumed; then after 70–265 years, dispersal continued in one major pulse to all remaining islands c. 1190–1290." Later migrants likely came from Tahiti and other south Pacific islands.

Although Captain James Cook recorded sighting Molokai in 1778, the first European sailor to visit the island was Captain George Dixon of the British Royal Navy in 1786. The first significant European influence came in 1832 when a Protestant mission was established at Kaluaʻaha on the East End of the island by the Reverend Harvey Hitchcock. The first farmer on Molokai to grow, produce and mill sugar and coffee commercially was Rudolph Wilhelm Meyer, an immigrant from Germany who arrived in 1850. He built the first and only sugar mill on the island in 1878, which is now a museum.

Ranching began on Molokai in the first half of the 19th century when King Kamehameha V set up a country estate on the island, which was managed by Meyer and became what is now the Molokai Ranch. In the late 1800s, Kamehameha V built a vacation home in Kaunakakai and ordered the planting of over 1,000 coconut trees in Kapuaiwa Coconut Grove.

Leprosy (also known as Hansen's disease) was among Eurasian diseases introduced to the Hawaiian islands by traders, sailors, workers and others who lived in societies where these diseases were endemic. Because of the islanders' lack of immunity to the new diseases, they suffered high rates of infection and death from smallpox, cholera, measles and whooping cough, as well as leprosy. Sugar planters were worried about the effects on their labor force and pressured the government to take action to control the spread of leprosy.

The legislature passed a control act requiring quarantine of people with leprosy. The government established Kalawao located on the isolated Kalaupapa peninsula on the northern side of Molokai, followed by Kalaupapa as the sites of a leper colony that operated from 1866 to 1969. Because Kalaupapa had a better climate and sea access, it developed as the main community. A research hospital was developed at Kalawao. The population of these settlements reached a peak of 1,100 shortly after the beginning of the 20th century.

In total over the decades, more than 8,500 men, women and children living throughout the Hawaiian islands and diagnosed with leprosy were exiled to the colony by the Hawaiian government and legally declared dead. This public health measure was continued after the Kingdom became a U.S. territory. Patients were not allowed to leave the settlement nor have visitors and had to live out their days here.

Arthur Albert St. Mouritz served as a physician to the leper settlement from 1884 to 1887. He explained how leprosy was spread.

Pater Damiaan de Veuster, a Belgian priest of the Congregation of the Sacred Hearts of Jesus and Mary served as a missionary for 16 years in the communities of sufferers of leprosy. Joseph Dutton, who served in the 13th Wisconsin Volunteer Infantry Regiment during the American Civil War and converted to Roman Catholicism in 1883, came to Molokai in 1886 to help Pater Damiaan and the rest of the population who suffered from leprosy. Pater Damiaan died at Kalaupapa in 1889 while Joseph Dutton died in Honolulu in 1931 at the age of 87. Mother Marianne Cope of the Sisters of Saint Francis of Syracuse, New York, brought six of her Sisters to work in Hawaiʻi with leprosy sufferers in the late 19th century, also serving on Molokai.

Both Father Damiaan and Mother Marianne have been canonized as Saints by the Roman Catholic Church for their charitable work and devotion to sufferers of leprosy. In December 2015, the cause of Joseph Dutton was formally opened, obtaining him the title Servant of God.

In the 1920s, people confined in the leper colony were treated with a new method devised by Alice Ball and involving chaulmoogra oil. In the 1940s, sulfonamide drugs were developed and provided a more effective treatment. Antibiotic Dapsone has been used for leprosy since 1945. Modern Multidrug therapy (MDT) remains highly effective, and people are no longer infectious after the first monthly dose.

In 1969, the century-old laws of forced quarantine were abolished. Former patients living in Kalaupapa today have chosen to remain here, most for the rest of their lives. In the 21st century, there are no persons on the island with active cases of leprosy, which has been controlled through medication, but some former patients chose to continue to live in the settlement after its official closure.

Over the years Molokai Ranch has also acted as a developer, establishing hotels and related amenities for resort tourists on their property. The local indigenous community fought for many decades to inhibit the development by Molokai Ranch in order to preserve their community and unique way of life. In some cases, protests have become violent, such as fence cutting, poisoning of the Ranch's exotic African Safari animals in 1994, an arson attack in Kaupoa in 1995, and the destruction of 5 mi (8.0 km) of Ranch water pipes in 1996.

In 2007, community residents organized the "Save Laʻau Point" movement to oppose Molokai Ranch's attempt to expand its resort operation. As a result, on March 24, 2008, Molokai Ranch, then the island's largest employer, decided to shut down all resort operations, including hotels, movie theater, restaurants, and golf course, and dismiss 120 workers. In September 2017 the company that owns Molokai Ranch, Singapore-based Guoco Leisure Ltd, put this 55,575 acres (22,490 ha) property, encompassing 35% of the island of Molokai, on the market for $260 million.

Due to the fight against development and tourism, Molokai has Hawaii's highest unemployment rate. The residents have fought hard to maintain a lifestyle based on indigenous subsistence practices. This lifestyle is not without challenges, however, and many live below the federal poverty line. One third of its residents use food stamps. As of 2014, the largest industry on the island is seed production for Monsanto and Mycogen Seeds, including GMO seeds.

The tourism industry on Molokai is relatively small, compared to the other islands in Hawaiʻi. Only 64,767 tourists visited Molokai in 2015. For decades, residents of Molokai have resisted private developers' attempts to increase tourism because of the irreparable changes to community and culture that are associated with a tourism industry. Accommodations are limited; as of 2014, only one hotel was open on the island. Most tourists find lodgings at rental condos and houses.

National Geographic Traveler magazine and the National Geographic Center for Sustainable Destinations conduct annual Destination Scorecard surveys, aided by George Washington University. In 2007, a panel of 522 experts in sustainable tourism and destination stewardship reviewed 111 selected human-inhabited islands and archipelagos around the world. Molokai ranked 10th among the 111 destination locales. The survey cited Molokai's undeveloped tropical landscape, environmental stewardship, and rich, deep Hawaiian traditions (the island's mana). The neighbor islands of Hawaii, Kauai, Maui and Oahu, ranked 50, 61, 81 and 104, respectively.

Molokai is believed to be the birthplace of the hula. The annual Molokaʻi Ka Hula Piko festival is held on this island.

Molokai can be reached by plane. Planes fly into Molokaʻi daily from other Hawaiian islands including Oʻahu (Honolulu and Kalaeloa), Maui (Kahului) and Hawaii (Kona), operated by Mokulele Airlines, Paragon Air and Hawaiian Airlines.

A ferry that formerly sailed between Molokai and Lāhainā Harbor, Maui closed operations on October 27, 2016. Sea Link President and Senior Capt. Dave Jung attributed the closure to competition from federally subsidized commuter air travel and declining ridership.

The island of Molokai is served by Molokaʻi General Hospital, which operates all day, every day. It is also serviced by Molokai Community Health Center and Molokai Family Health Center.

The island public school system includes four elementary schools, one charter school, one middle school, and one high school. There is also a community college. The island has one private middle/high school.

The island contains many parks and other protected areas, but most parks do not have service staff, potable water, or restroom facilities. Parks within the Maui County parks jurisdiction include Palaʻau State Park, Kiowea Beach Park, Kakahaiʻa National Wildlife Refuge, Molokaʻi Forest Reserve, Pelekunu Preserve, George Murphy Beach Park, Hālawa Beach Park, and Papohaku Beach Park (with a 3 mi (4.8 km) beach) in the portion within Maui County. Today Kalawao County is preserved by the Kalaupapa National Historical Park (accessible by guided mule or hiking tour).

The island can be traversed by a two-lane highway running east to west (highways 450 and 460). Highway 470 is a spur up to the barrier mountains of Kalawao County and the Kalaupapa peninsula. By land this area (Kalaupapa) can only be reached by a hiking trail. Mule rides on the trail were suspended in 2018 when the trail temporarily closed due to a landslide and bridge damage. Most access to the Kalaupapa peninsula is by sea.

Maui Economic Opportunity operates public transportation on Molokai.

• Mother Marianne Cope, 19th-century nun and saint
• Father Damien de Veuster, 19th-century Catholic priest and saint
• Joseph Dutton, Catholic missionary who worked with Father Damien
• Peter Johnson Gulick, Protestant missionary
• Harvey Rexford Hitchcock, Protestant missionary
• Harvey Rexford Hitchcock, Jr., 1913 College Football All-America Team
• John S. K. Kauwe III – Biologist and president of Brigham Young University–Hawaii
• Melveen Leed, singer
• Linda Lingle, 6th Governor of Hawaiʻi
• Keith Luuloa, professional baseball player (Anaheim Angels)
• Rudolph Wilhelm Meyer, politician and agricultural businessman in Hawaiʻi
• William Ragsdale, popular Hawaiian attorney and politician, who served as superintendent at Kalaupapa for four years (1874–1878)
• Arthur Albert St. Mouritz, physician to the leper settlement in Molokai, Hawaii, from 1884 to 1887. He explained how leprosy was spread.
• Kirby Wright, poet and writer
• Lois-Ann Yamanaka, poet and novelist

• Nuʻakea, High Chieftess of Molokaʻi
• Hualani, High Chieftess of Molokaʻi
• Keʻoloʻewa, High Chief of Molokaʻi
• Kapau-a-Nuʻakea, Chieftess of Molokaʻi
• Kamauliwahine, Lady of Molokaʻi
• Kanipahu, High Chief of Molokaʻi
• Kamauaua, High Chief of Molokaʻi
• Kaupeepeenuikauila, Prince of Molokaʻi
• Kahokuohua, High Chief of Molokaʻi
• Kalanipehu, High Chief of Molokaʻi
• Kanealai, High Chieftess and Queen Regent of Molokaʻi in the 18th century

• Hoolehua
• Kalaupapa
• Kalawao
• Kaunakakai
• Kualapuu
• Maunaloa
• ʻUalapuʻe
• Halawa

• Alii Aimoku of Molokai
• Father Damien of Molokai
• National Register of Historic Places listings in Hawaii#Molokai
• Koolau the Leper, a short story by Jack London

• Coffman, Tom (2003). The Island Edge of America: A Political History of Hawai'i. University of Hawaii Press. ISBN 978-0-8248-2662-8.
• Engledow, Jill (March 2007). "Where Tradition Holds Sway". Maui Nō Ka ʻOi Magazine. 11 (2). Archived from the original on 2009-07-20. Retrieved 2008-05-20. Article about traditional hula halau on Molokaʻi
• Farber, Joseph M. (1997). Ancient Hawaiian Fishponds: Can Restoration Succeed on Molokaʻi?. Neptune House Publications. ISBN 978-0-9659782-0-0.
• Lee, Pali Jae Kealohilani (1984). Moʻolelo O Na Po Makole. Paia-Kapela-Willis, ʻOhana.
• Lo, Catharine. "On the Rocks". Hana Hou!. 9 (6). Article about Hawaiian limpets, a traditional delicacy known locally as ʻopihi.
• Tayman, John (11 May 2010). The Colony: The Harrowing True Story of the Exiles of Molokai. Simon and Schuster. ISBN 978-1-4165-5192-8.

• Starbird, Ethel A. (August 1981). "Molokai—Forgotten Hawaii". National Geographic. Vol. 160, no. 2. pp. 188–219. ISSN 0027-9358. OCLC 643483454.

• Molokaʻi travel guide from Wikivoyage
• Official Molokaʻi Visitors Association website
• The Molokaʻi Dispatch, weekly print community newspaper