Adjacent counties

• Aroostook County – north
• Washington County – southeast
• Hancock County – south
• Waldo County – southwest
• Somerset County – west
• Piscataquis County – northwest

National protected area

• Sunkhaze Meadows National Wildlife Refuge

2000 census

At the 2000 census there were 144,919 people, 58,096 households, and 37,820 families living in the county. The population density was 43 people per square mile (17 people/km²). There were 66,847 housing units at an average density of 20 per square mile (7.7/km²). The county's racial makeup was 96.60% White, 0.49% Black or African American, 1.00% Native American, 0.70% Asian, 0.03% Pacific Islander, 0.23% from other races, and 0.96% from two or more races. 0.61% of the population were Hispanic or Latino of any race. 17.8% were of English, 17.3% United States or American, 14.0% French, 13.0% Irish and 6.7% French Canadian ancestry. 95.8% spoke English and 2.3% French as their first language.^[11] There were 58,096 households, of which 30.10% had children under the age of 18 living with them, 51.50% were married couples living together, 9.90% had a female householder with no husband present, and 34.90% were non-families. 26.70% of households were one person and 10.00% were one person aged 65 or older. The average household size was 2.38 and the average family size was 2.88.

The age distribution was 22.80% under the age of 18, 11.30% from 18 to 24, 29.00% from 25 to 44, 23.80% from 45 to 64, and 13.10% 65 or older. The median age was 37 years. For every 100 females there were 95.30 males. For every 100 females age 18 and over, there were 92.30 males.

The median household income was $34,274 and the median family income was $42,206. Males had a median income of $32,824 versus $23,346 for females. The per capita income for the county was $17,801. About 9.70% of families and 13.70% of the population were below the poverty line, including 15.00% of those under age 18 and 11.10% of those age 65 or over.

2010 census

At the 2010 census, there were 153,923 people, 62,966 households, and 38,917 families living in the county.^[12] The population density was 45.3 inhabitants per square mile (17.5/km²). There were 73,860 housing units at an average density of 21.7 units per square mile (8.4 units/km²).^[13] The county's racial makeup was 95.4% white, 1.2% American Indian, 0.9% Asian, 0.8% black or African American, 0.2% from other races, and 1.5% from two or more races. Those of Hispanic or Latino origin made up 1.1% of the population.^[12] In terms of ancestry, 20.9% were English, 17.2% were Irish, 9.4% were American, 7.1% were German, 6.0% were French Canadian, and 5.9% were Scottish.^[14]

Of the 62,966 households, 27.5% had children under the age of 18 living with them, 47.1% were married couples living together, 10.3% had a female householder with no husband present, 38.2% were non-families, and 28.0% of households were made up of individuals. The average household size was 2.33 and the average family size was 2.82. The median age was 39.9 years.^[12]

The county's median household income was $42,658 and the median family income was $54,271. Males had a median income of $41,094 versus $31,910 for females. The county's per capita income was $22,977. About 10.1% of families and 15.7% of the population were below the poverty line, including 20.4% of those under age 18 and 9.2% of those age 65 or over.^[15]

Voter registration

Cities

• Bangor (county seat)
• Brewer
• Old Town

Towns

Plantations

• Carroll Plantation
• Drew Plantation
• Seboeis Plantation
• Webster Plantation

Census-designated places

Unorganized territories

Indian reservation

• Penobscot Indian Island Reservation