Alfonse Marcello D'Amato (born in Brooklyn, New York, on August 1, 1937) is a former United States Senator who represented the state of New York for 18 years from 1981 to 1999. He subsequently founded a lobbying firm, Park Strategies.

In 1980—after 25 years of involvement in the politics and government of Long Island—D'Amato defeated the four-term liberal Republican Sen. Jacob Javits for the Republican nomination for Senator and then in the general election for that office. D'Amato was re-elected in 1986 and 1992 before losing his fourth U.S. Senate election campaign to nine-term New York Congressman Chuck Schumer in 1998.

During his term as US Senator, he was known for supporting President Ronald Reagan on non-economic issues such as abortion. He agreed with President Bill Clinton both in 1993, for opening service in the armed forces to non-heterosexuals, and in 1996 for the Defense of Marriage Act, which denied federal recognition to same-sex marriages.

As of 2023, D'Amato is the last Republican to have represented New York in the U.S. Senate.