Fairmount is a hamlet (and census-designated place) in Onondaga County, New York, United States. The Fairmount area was originally part of the New York State Salt Reservation, but was annexed to the town of Camillus in 1834. Prior to that date, census enumerations for Fairmount were included in the town of Onondaga census. The name originates from 1798 when engineer and politician James Geddes built his estate, called "Fair Mount" at the intersection of Genesee Road (now West Genesee Street) and Onondaga Road. During the mid-19th century, the hamlet was also known as Tyler or Jeromeville. It had its own post office until about 1890. It has had its own fire department since 1942.The Fair Mount mansion was demolished in 1929. The Brockway Tavern building, located on the northwest corner of West Genesee and Onondaga, formerly housed a restaurant and later a funeral home, now houses a credit union. The house was built c. 1808 and survives as one of the oldest structures in the hamlet.Farmland in the hamlet was developed into residential tracts from the 1890s through the 1990s. A large area of undeveloped land, formerly used for quarrying and a munitions factory in the 19th and early 20th centuries, borders Fairmount to the south at Split Rock, and is not considered to be seriously polluted.Fairmount is a western suburb of Syracuse, New York, located in the far southeastern corner of the town of Camillus. Its zip code is 13219 (Syracuse). It is located within the West Genesee Central School District. The population was 10,224 at the 2010 census.