Montgomery County is a county in the U.S. state of New York. As of the 2020 census, the population was 49,532. The county seat is Fonda. The county was named in honor of Richard Montgomery, an American Revolutionary War general killed in 1775 at the Battle of Quebec. The county is part of the Mohawk Valley region of the state.

Fonda is a village in and the county seat of Montgomery County, New York, United States. The population was 668 at the 2020 census. The village is named after Douw Fonda, a Dutch-American settler who was killed and scalped in 1780, during a Mohawk raid in the Revolutionary War, when the tribe was allied with the British.