Maine ranked 40th in population in the US with an estimated total of 1,294,464 in 2002, an increase of 1.5% since 2000. Between 1990 and 2000, Maine's population grew from 1,227,928 to 1,274,923, an increase of 3.8%. The population is projected to reach 1.4 million by 2025. The population density in 2000 was 41.3 persons per sq mi.

In 2000 the median age was 38.6. Persons under 18 years old accounted for 23.6% of the population while 14.4% were age 65 or older.

The area that now comprises the state of Maine was sparsely settled throughout the colonial period. At statehood, Maine had 298,335 residents. The population doubled by 1860, but then grew slowly until the 1970s, when its growth rate outstripped the nation's.

More than half the population lives on less than one-seventh of the land, within 25 mi (40 km) of the Atlantic coast, and almost half of the state is virtually uninhabited. Although almost half of Maine's population is classified as urban; much of the urban population lives in towns and small cities. The state's major cities, all with populations under 100,000, are Portland, Bangor, and Lewiston-Auburn.