Maine ( MAYN) is a state in the New England region of the United States, and the northeastern most state in the Lower 48. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and northwest, and shares a maritime border with Nova Scotia. Maine is the largest state in New England by total area, nearly larger than the combined area of the remaining five states. Of the 50 U.S. states, it is the 12th-smallest by area, the 9th-least populous, the 13th-least densely populated, and the most rural. Maine's capital is Augusta, and its most populous city is Portland, with a total population of 68,408, as of the 2020 census.

The territory of Maine has been inhabited by Indigenous populations for about 12,000 years, after the glaciers retreated during the last ice age. At the time of European arrival, several Algonquian-speaking nations governed the area and these nations are now known as the Wabanaki Confederacy. The first European settlement in the area was by the French in 1604 on Saint Croix Island, founded by Pierre Dugua, Sieur de Mons. The first English settlement was the short-lived Popham Colony, established by the Plymouth Company in 1607. A number of English settlements were established along the coast of Maine in the 1620s, although the rugged climate and conflict with the local Indigenous people caused many to fail. As Maine entered the 18th century, only a half dozen European settlements had survived. Loyalist and Patriot forces contended for Maine's territory during the American Revolution. During the War of 1812, the largely undefended eastern region of Maine was occupied by British forces with the goal of annexing it to Canada via the Colony of New Ireland, but returned to the United States following failed British offensives on the northern border, mid-Atlantic and south which produced a peace treaty that restored the pre-war boundaries. Maine was part of the Commonwealth of Massachusetts until 1820 when it voted to secede from Massachusetts to become a separate state. On March 15, 1820, under the Missouri Compromise, Maine was admitted to the Union as the 23rd state.

Today, Maine is known for its jagged, rocky Atlantic Ocean and bay-shore coastlines, mountains, heavily forested interior, and its cuisine, particularly wild lowbush blueberries and seafood such as lobster and clams. Coastal and Down East Maine have emerged as important centers for the creative economy, especially in the vicinity of Portland, which has also brought gentrification to the city and its metropolitan area.