Fort Ontario | |
 View from Fort Ontario | |
   | |
| Location | 1 E. 4th St. and Lake Ontario, Oswego, New York |
|---|---|
| Coordinates | 43°27′57″N 76°30′29″W / 43.46583°N 76.50806°W |
| Area | 36 acres (15 ha) |
| Built | 1839 |
| NRHP reference No. | 70000426[1] |
| NYSRHP No. | 07540.000009 |
| Significant dates | |
| Added to NRHP | December 18, 1970 |
| Designated NYSRHP | June 23, 1980 |
Fort Ontario is an American historic bastion fort situated by the City of Oswego in Oswego County, New York. It is owned by the state of New York and operated as a museum known as Fort Ontario State Historic Site. Fort Ontario is located on the east side of the Oswego River on high ground overlooking Lake Ontario.