Named Islands

• Martha's Vineyard
  • Chappaquiddick Island, Edgartown
  • Skiff’s Island, south of Chappaquiddick^[6]
  • Ferry Boat Island, Tisbury
  • Wood Island, Oak Bluffs
  • Brush Island, Oak Bluffs
  • Gravel Island, Oak Bluffs
  • Sarson Island, Oak Bluffs
  • Haystack Island, Oak Bluffs
  • Edy’s Island, Chilmark
  • Mayhew Island, Chilmark
  • Beach Grass Island, Chilmark
  • Strawberry Island, Chilmark
  • Gull Island, Chilmark
  • Great Island, Chilmark
  • Nomans Land, Chilmark
• Elizabeth Islands, Gosnold
  • Naushon Island
  • Nashawena Island
  • Pasque Island
  • Cuttyhunk Island
  • Penikese Island
  • Gull Island
  • Barlet Island
  • Rock Island
  • Uncatena Island
  • Nonamesset Island
  • Veckatimest Island
  • Monohansett Island
  • Cedar Island
  • Bull Island
  • Pine Island
  • Weepecket Islands

Nearby counties

• Barnstable County, Massachusetts – northeast
• Plymouth County, Massachusetts – north
• Bristol County, Massachusetts – northwest
• Nantucket County, Massachusetts – east

National protected area

• Nomans Land Island National Wildlife Refuge

2020 census

Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos can be of any race.

2010 census

At the 2010 census, there were 16,535 people, 7,368 households, and 4,221 families living in the county.^[14] The population density was 160.2 inhabitants per square mile (61.9/km²). There were 17,188 housing units at an average density of 166.5 per square mile (64.3/km²).^[15] The racial makeup of the county was 87.6% white, 3.1% black or African American, 1.1% American Indian, 0.8% Asian, 0.1% Pacific islander, 3.9% from other races, and 3.4% from two or more races. Those of Hispanic or Latino origin made up 2.3% of the population.^[14]

The largest ancestry groups were:^[16]

Of the 7,368 households, 25.9% had children under the age of 18 living with them, 44.1% were married couples living together, 8.9% had a female householder with no husband present, 42.7% were non-families, and 33.4% of households were made up of individuals. The average household size was 2.22 and the average family size was 2.81. The median age was 45.3 years.^[14]

The median household income was $62,407 and the median family income was $77,231. Males had a median income of $43,850 versus $41,994 for females. The per capita income for the county was $33,390. About 5.5% of families and 8.6% of the population were below the poverty line, including 4.3% of those under age 18 and 7.2% of those age 65 or over.^[17]

2000 census

At the 2000 census there were 14,987 people, 6,421 households, and 3,788 families living in the county. The population density was 144 inhabitants per square mile (56/km²). There were 14,836 housing units at an average density of 143 per square mile (55/km²). The racial makeup of the county was 90.69% White, 2.40% Black or African American, 1.71% Native American, 0.46% Asian, 0.07% Pacific Islander, 1.48% from other races, and 3.19% from two or more races. 1.03% of the population were Hispanic or Latino of any race. 20.4% were of English, 13.3% Irish, 8.6% Portuguese, 6.4% Italian and 5.7% American ancestry, 93.1% spoke English, 3.7% Portuguese and 1.7% Spanish as their first language and 0.285% speak Irish at home.^[18] Of the 6,421 households 28.40% had children under the age of 18 living with them, 45.40% were married couples living together, 9.80% had a female householder with no husband present, and 41.00% were non-families. 32.00% of households were one person and 11.10% were one person aged 65 or older. The average household size was 2.30 and the average family size was 2.91.

The age distribution was 22.70% under the age of 18, 5.50% from 18 to 24, 29.60% from 25 to 44, 27.80% from 45 to 64, and 14.40% 65 or older. The median age was 41 years. For every 100 females, there were 95.60 males. For every 100 females age 18 and over, there were 92.10 males.

The median household income was $45,559 and the median family income was $55,018. Males had a median income of $38,945 versus $30,346 for females. The per capita income for the county was $26,472. About 5.00% of families and 7.30% of the population were below the poverty line, including 10.40% of those under age 18 and 5.30% of those age 65 or over.

Real estate

As of the fourth quarter 2021, the median value of homes in Dukes County was $883,820, an increase of 22.3% from the prior year.^[19]

Demographic breakdown by town

Religion

Voter registration

Towns

• Aquinnah (formerly Gay Head)
• Chilmark
• Edgartown (shire town or county seat)
• Gosnold
• Oak Bluffs
• Tisbury
• West Tisbury

Census-designated places

• Edgartown
• Oak Bluffs
• Vineyard Haven

Other villages

• Cuttyhunk
• Menemsha