Fish Creek is a moderately sized river emptying into the eastern end of Oneida Lake in Oneida County, New York. Formed by the confluence of its east and west forks near the hamlet of Blossvale, the creek flows southwest for 11 miles (18 km), through the towns of Annsville and Vienna. The last mile of the creek is channelized to form part of the Erie Canal, which joins the lake at Sylvan Beach. The creek drains approximately 528.9 square miles (1,370 km2) of the Tug Hill plateau country in Central New York.
The largest tributary of Oneida Lake, Fish Creek contributes about 50% of the lake's total inflow.
Although the main stem is short, the East Branch stretches 42 miles (68 km), and the West Branch is 28 miles (45 km) long. Measured to its furthest headwaters along the East Branch in Lewis County, Fish Creek is 53 miles (85 km) long, draining parts of Oneida, Lewis and Oswego Counties. Excepting the east and west branches, the only major tributary that joins Fish Creek proper is Wood Creek, which enters from the east via the Erie Canal. Nearly all of the watershed is rural, with the only significant towns being (from roughly north-to-south) Florence, Williamstown, Camden, Annsville, and Vienna. The East Branch contributes about 46% of the total flow in Fish Creek; the West Branch 42%; and Wood Creek, about 12%.
The East Branch Fish Creek originates in southern Lewis County, at the confluence of Sixmile and Sevenmile Creeks about 10 miles (16 km) west of Lyons Falls. It flows generally south, receiving Sucker Brook from the east and entering a narrow gorge, where it is impounded in the small City of Rome Reservoir. Below the reservoir it is joined by Florence Creek from the west, before flowing past Taberg to its mouth and confluence with the West Branch.