New York’s 27th congressional district was a congressional district for the United States House of Representatives in western New York. It included all of Orleans, Genesee, Wyoming, and Livingston counties and parts of Erie, Monroe, Niagara, and Ontario counties. The district contained most of the eastern and southern suburbs of Buffalo, most of the southern suburbs of Rochester, as well as large rural areas to the east and south. The seat was last occupied by Republican Chris Jacobs, who won a special election on June 23, 2020. Previously, it had been vacant from October 1, 2019, when Republican incumbent Chris Collins resigned after pleading guilty to charges of insider trading.

Niagara County is in the U.S. state of New York. As of the 2020 census, the population was 212,666. The county seat is Lockport. The county name is from the Iroquois word Onguiaahra; meaning the strait or thunder of waters. The county is part of the Western New York region of the state.