Deer Park is a hamlet and census-designated place (CDP) in the town of Babylon, Suffolk County, New York, United States. The population was 27,745 at the 2010 census.
Deer Park is a residential hamlet located in the pine barrens in the northeast corner of the town of Babylon. It grew out of Jacob Conklin's 1610 settlement of the Half Way Hollow Hills, later Wheatley Heights. Charles Wilson started what is now Deer Park in 1853 about eleven years after the Long Island Rail Road arrived in 1842-when he established a large and productive farm. A post office was opened in 1851, closed in 1872 and re-opened on July 1, 1873. Deer Park had an elementary school in 1874. Prior to 1923, the Deer Park School District took in Deer Park and Wyandanch.
Farming was a staple of this small town for most of its history. Known as the "fruit basket" of New York state, the area was also famed for its dahlia cultivation. It was not until the effects of the post-World War II boom reached Deer Park that its economy ceased to be agricultural.
Deer Park had two industries before 1940: the Walker and Conklin firm baked red bricks in West Deer Park (now Wheatley Heights), and the Golden Pickle Works (1902) prepared pickles in Deer Park.