Onondaga County, New York

Onondaga County is a county in New York, United States, about 145 miles west of Albany and 85 miles east of Rochester. It had a population of 476,516 at the 2020 census, an estimated 471,129 by 2024, and covers 806 square miles (2,090 km2) centred near 43°03′N 76°09′W.

Syracuse is the county seat and its only city; its postal code is 13202. The county holds 1 city, 15 incorporated villages and 13 major unincorporated communities across its 19 towns, and it runs on Eastern Time. Its FIPS code is 36067.

Towns & Villages in Onondaga County

Onondaga County has one city and 15 incorporated villages, each with its own local government. Alongside them are 13 Census-designated places — unincorporated communities the Census Bureau tracks for statistics but that have no village or city government of their own. CDP stands for census designated place. The county’s 19 towns are the civil divisions each municipality sits inside, the New York equivalent of a township elsewhere.

Beyond the incorporated places, 13 Census-designated places account for most of the county’s remaining population:

Two confusable pairs are worth flagging. De Witt (two words) is the unincorporated CDP hugging Syracuse’s eastern edge; DeWitt (one word) is the town that contains it and also the village of East Syracuse. And several villages share their exact name with the town around them — Manlius, Marcellus, Camillus, Elbridge, Tully and Fabius are each both a village and a separate, larger town, a common pattern in New York’s local government structure. This page’s older version also carried roughly 180 additional names pulled from a federal places gazetteer — trailer parks, road junctions and long-defunct rural hamlets such as Amber, Cardiff and Watervale — with no population, ZIP or governing body attached to any of them. None could be verified against a current municipal or Census source, so they have been dropped rather than repeated as unconfirmed fact.

Geography

Onondaga County spans two landscapes. Its northern half lies in the flat Erie-Ontario Lowlands, drained toward Lake Ontario by the Seneca and Oneida rivers; its southern half rises into the Appalachian Upland, a hilly plateau that reaches its highest points near the Town of Fabius. Onondaga Lake, on Syracuse’s northwest side, was the county’s dominant 19th-century industrial resource and is now a federal Superfund cleanup site under active remediation. Skaneateles Lake, one of the Finger Lakes, forms part of the county’s southwestern edge and supplies the city of Syracuse’s drinking water without filtration, one of the few unfiltered municipal water supplies left in the country. Otisco Lake, the smallest of the Finger Lakes, sits entirely within the county’s southern towns.

Oswego County lies to the north, Madison County to the east, Cortland County to the south, and Cayuga County to the west. Oswego County, Madison County and Cayuga County all have pages on this site; Cortland County borders Onondaga to the south but has no page here yet.

Demographics

Onondaga County had a population of 476,516 at the 2020 census. The latest estimate, from 2024, puts the county at 471,129, a slight decline that reflects broader Upstate New York trends. Syracuse and Baldwinsville are the county’s two largest communities by a wide margin, followed by the CDPs of De Witt and Fairmount. Median household income runs $76,945, below New York State’s overall figure of $82,100. Population density works out to about 613 people per square mile of land, concentrated heavily in Syracuse and the ring of towns immediately around it.

Economy & Local Life

Health care and social assistance is the county’s largest employment sector, with about 40,598 workers, followed by educational services at 34,168 and retail trade at 24,009. SUNY Upstate Medical University is the county’s single largest employer, with nearly 11,000 staff, and anchors a hospital and research corridor alongside Syracuse University, Le Moyne College and Onondaga Community College. The Town of Clay, in the county’s north, is the site of Micron Technology’s planned semiconductor manufacturing complex, a project valued at roughly $125 billion that is the largest private economic development project in New York State history. The county’s biggest annual event is the Great New York State Fair, held each August into early September on the fairgrounds in the Town of Geddes, one of the oldest state fairs in the country.

History

New York’s legislature organized Onondaga County on 5 March 1794, carving it out of Herkimer County. It takes its name from the Onondaga Nation, one of the original Five Nations of the Haudenosaunee Confederacy and traditionally its central fire-keepers. Onondaga Nation territory, roughly six miles south of Syracuse in the Town of Onondaga, remains under Onondaga governance today; it is one of the few Indigenous territories in the state never confirmed by a treaty ratified by the US Senate, a status that has fed ongoing land-rights litigation.

The Erie Canal reached Syracuse in 1825, and the salt springs around Onondaga Lake had already made the area a major salt-producing center, earning Syracuse the nickname “Salt City.” Canal access let local producers ship salt nationwide, and the industry, along with canal trade generally, drove the county’s 19th-century growth before declining in the early 1900s as western salt deposits undercut it.

Getting There

Interstate 81 runs north-south through Syracuse, Interstate 90 (the New York State Thruway) crosses the county east-west along its northern edge, Interstate 481 loops around the city’s east side, and Interstate 690 runs east-west through downtown Syracuse.

• Rochester — about 85 miles west
• Utica — about 50 miles east
• Ithaca — about 55 miles south
• Watertown — about 70 miles north

Syracuse Hancock International Airport, on the city’s north side near the Salina-DeWitt line, is the nearest major commercial airport and sits inside the county itself. Amtrak’s Empire Service and Lake Shore Limited trains stop at the William F. Walsh Regional Transportation Center in downtown Syracuse.

Frequently Asked Questions

Where is Onondaga County located?
It sits in Central New York, about 145 miles west of Albany and 85 miles east of Rochester, bordered by Oswego, Madison, Cortland and Cayuga counties.

What is the population of Onondaga County?
476,516 at the 2020 census, with a 2024 estimate of 471,129.

How big is Onondaga County?
806 square miles (2,090 km2) in total, of which 778 square miles are land and 27 square miles are water.

What is the county seat of Onondaga County?
Syracuse, the county’s only city, is the county seat.

How many towns and villages are in Onondaga County?
One city, 15 incorporated villages, 19 towns, and 13 Census-designated places, listed in the tables above.

What ZIP codes does Onondaga County use?
13202 for downtown Syracuse, plus separate codes for each village — 13027 for Baldwinsville, 13212 for North Syracuse, 13209 for Solvay and 13104 for Manlius among them. Most CDPs share a neighboring village or Syracuse ZIP rather than having one of their own.

What is Onondaga County known for?
The Onondaga Nation’s homeland, the Great New York State Fair, Syracuse University, and the salt industry that built 19th-century Syracuse.

More counties in this state: Towns and villages in New York.