According to the United States Census Bureau, the town has a total area of, of which, of it is land and is water. Located beside Passamaquoddy Bay, Perry is drained by the St. Croix River.
As of the census of 2010, there were 889 people, 362 households, and 253 families living in the town. The population density was. There were 551 housing units at an average density of. The racial makeup of the town was 85.5% White, 10.5% Native American, 0.1% Asian, 0.3% Pacific Islander, 0.3% from other races, and 3.3% from two or more races. Hispanic or Latino of any race were 1.0% of the population. There were 362 households of which 30.1% had children under the age of 18 living with them, 57.2% were married couplesliving together, 6.4% had a female householder with no husband present, 6.4% had a male householder with no wife present, and 30.1% were non-families. 22.7% of all households were made up of individuals and 6.4% had someone living alone who was 65 years of age or older. The average household size was 2.46 and the average family size was 2.89. The median age in the town was 44 years. 23.8% of residents were under the age of 18; 3.6% were between the ages of 18 and 24; 24.5% were from 25 to 44; 34.2% were from 45 to 64; and 13.9% were 65 years of age or older. The gender makeup of the town was 48.0% male and 52.0% female.
2000 census
As of the census of 2000, there were 847 people, 331 households, and 238 families living in the town. The population density was 28.8 people per square mile. There were 529 housing units at an average density of 18.0 per square mile. The racial makeup of the town was 86.19% White, 0.24% African American, 11.92% Native American, 0.12% Pacific Islander, and 1.53% from two or more races. There were 331 households out of which 34.1% had children under the age of 18 living with them, 55.3% were married couples living together, 10.0% had a female householder with no husband present, and 27.8% were non-families. 21.5% of all households were made up of individuals and 8.8% had someone living alone who was 65 years of age or older. The average household size was 2.54 and the average family size was 2.92. In the town, the population was spread out with 27.5% under the age of 18, 7.4% from 18 to 24, 27.2% from 25 to 44, 26.7% from 45 to 64, and 11.2% who were 65 years of age or older. The median age was 37 years. For every 100 females, there were 92.9 males. For every 100 females age 18 and over, there were 99.4 males. The median income for a household in the town was $27,788, and the median income for a family was $35,104. Males had a median income of $31,442 versus $22,292 for females. The per capita income for the town was $14,285. About 15.9% of families and 17.5% of the population were below the poverty line, including 17.2% of those under age 18 and 32.5% of those age 65 or over.
