South Farmingdale is a hamlet and census-designated place (CDP) in the Town of Oyster Bay in Nassau County, on the South Shore of Long Island, in New York, United States.

[4][5] A railroad station named South Farmingdale previously existed in the hamlet on the Central Branch of the Long Island Rail Road.

[6][7] According to the United States Census Bureau, South Farmingdale has a total area of 2.2 square miles (5.7 km2), all land.

[5] In the 2024 U.S. presidential election, the majority of South Farmingdale voters voted for Donald J. Trump (R).

[5] No Long Island Rail Road stations are located within the hamlet – although the LIRR's Central Branch forms its northern border.

[5] Additionally, the now-closed South Farmingdale station was once located on the Central Branch, within the hamlet; it closed in the 1970s.

[6] It was along this stretch of the Central Branch that Mile-a-Minute Murphy set a record in 1899, pedaling a bicycle for one mile behind a train in less than one minute.

[19][20] PSEG Long Island provides power to all homes and businesses within South Farmingdale.

[19][21] South Farmingdale is located within the Nassau County Sewage District and is connected to its sanitary sewer network.

[23] A small portion of the hamlet, meanwhile, is located within the boundaries of (and is thus served by) the North Massapequa Fire District.

[5] South Farmingdale is served by the Nassau County Police Department's 8th Precinct, with RMPs 816 and 817 assigned as the patrol cars for the hamlet.