According to the United States Census Bureau, the hamlet has a total area of, As of the census of 2010, there were 17,862 people, and 5,289 households with an average of 3.26 persons per household residing in the hamlet. The population density was. The racial makeup of the CDP was 35.8% African American, 27.5% White, 1.4% Native American, 11.2% Asian, 0.1% Pacific Islander, 12.8% from other races, and 6.7% from two or more races. Hispanic or Latino of any race were 34.7% 6,237 of the population. The population in North Amityville was 7.0% under the age of 5, 27.0% under the age of 18, and 12.2% over the age of 65. Females make up 53.9% of the population. There were 5,636 housing units, of which 25.8% were in multi-unit structures. The homeownership rate was 62.3%. The median value of owner-occupied housing units was $339,100. 5.4% of housing units were vacant and 39.4% of occupied housing units were occupied by renters. The median income for a household in the hamlet was $90,502. 2.8% of the population were below the poverty line.
North Amityville is served by three public school districts. Most residents are within the confines of the Copiague Union Free School District, while other portions are within the Amityville Union Free School District and the Farmingdale Union Free School District. West of Bayview Avenue, northwest of Albany Avenue, south of an imaginary border that stretches from Albany Avenue to Johnson Street, west of another unclear border that cross the properties between Johnson Street, Dubois Avenue, Columbus Boulevard, and Great Neck Road, and southwest of Great Neck Road, is within the Amityville Union Free School District. Northeast of Great Neck Road and west of an imaginary line that stretches from the northeastern corner of the Columbus Boulevard/Great Neck Road intersection to the Southern State parkway just west of Cedar Road, is within the Farmingdale Union Free School District. There is only one public school that is entirely located in North Amityville: Northeast School, serving Pre-K and Kindergarten in the Amityville School District. Walter G. O'Connell Copiague High School
The Long Island Rail Road does not have a branch in North Amityville. Instead, residents are in close proximity to the Copiague & the Amityville. Operating under the Suffolk County Transit, several buses that serve the hamlet include:
