Ronkonkoma (pronounced ron-kon-ca-muh) is a census-designated place (CDP) on Long Island in the Town of Islip, Suffolk County, New York, United States. The population was 20,029 at the 2000 census. The Ronkonkoma post office has the ZIP code of 11779, and serves parts of several hamlets and CDPs adjacent to Ronkonkoma also.
Since 1988, Ronkonkoma has been the end of electrification along the Long Island Rail Road's Main Line. The track between Hicksville and Ronkonkama has long been referred to as the Ronkonkoma Branch.
Ronkonkoma is also home to Long Island MacArthur Airport (sometimes referred to simply as Islip Airport), airport code ISP, which is owned and operated by the Town of Islip.