Irondequoit Bay is a large body of water located in northeastern Monroe County, New York. The bay, roughly 0.5 miles (0.80 km) wide and 4 miles (6.4 km) in length, is fed by Irondequoit Creek to the south and flows into Lake Ontario at its northern end. On average, the surface of Irondequoit Bay rests at 245 feet (75 m) above sea level and is 80 feet (24 m) deep at its deepest point a short distance north of the Irondequoit Bay Bridge carrying the six-lane New York State Route 104 over the bay.

Monroe County is a county in the U.S. state of New York, located along Lake Ontario's southern shore. As of 2022, the population was 752,035, according to Census Bureau estimates. Its county seat and largest city is Rochester. The county is named after James Monroe, the fifth president of the United States. Monroe County is part of the Rochester, NY Metropolitan Statistical Area. The county is part of the Finger Lakes region of the state.