Edward Irving Koch (/kɒtʃ/ KOTCH; December 12, 1924 – February 1, 2013) was an American politician. He served in the United States House of Representatives from 1969 to 1977 and was mayor of New York City from 1978 to 1989.

Koch was a lifelong Democrat who described himself as a "liberal with sanity". The author of an ambitious public housing renewal program in his later years as mayor, he began by cutting spending and taxes and cutting 7,000 employees from the city payroll. He was the city's second Jewish mayor after his predecessor Abraham Beame. He crossed party lines to endorse Rudy Giuliani for mayor of New York City in 1993, Al D'Amato for Senate in 1998, Michael Bloomberg for mayor of New York City in 2001, and George W. Bush for president in 2004.

A popular figure, Koch rode the New York City Subway and stood at street corners greeting passersby with the slogan "How'm I doin'?" He was a lifelong bachelor, had no children and did not disclose his sexuality during his lifetime.

Koch was first elected mayor of New York City in 1977 and was re-elected in 1981 with 75% of the vote. He was the first New York City mayor to win endorsement on both the Democratic and Republican party tickets. In 1985, Koch was elected to a third term with 78% of the vote. His third term was fraught with scandal regarding political associates (although the scandal never touched him personally) and with racial tensions, including the killings of Michael Griffith and Yusuf Hawkins. In a close race, Koch lost the 1989 Democratic primary to his successor, David Dinkins.

Koch was born in the Crotona Park East section of the Bronx in New York City, the son of Yetta (or Joyce, née Silpe) and Louis (Leib) Koch, Polish-Jewish immigrants from Kozliv and Uścieczko (Ustechko) in Eastern Galicia, both located in Ternopil Oblast in western Ukraine. He came from a family of Conservative Jews who resided in Newark, New Jersey, where his father worked at a theater. As a child, he worked as a hatcheck boy in a Newark dance hall. He graduated from South Side High School in Newark in 1941.

In 1943, he was drafted into the United States Army. Koch did his basic training at Camp Croft, S.C., in 1943 before entering the Army Specialized Training Program. He then joined the 104th Infantry Division. On 27 August 1944, he departed New York City, landing in Cherbourg, France, on 7 September 1944. He earned a European-African-Middle Eastern Campaign Medal with two campaign stars, a World War II Victory Medal, and the Combat Infantryman Badge for service in the European Theater of Operations. After V-E Day, because he could speak German, Koch was sent to Bavaria to help remove Nazi public officials from their jobs and find non-Nazis to take their place. He was honorably discharged with the rank of sergeant in 1946.

Koch returned to New York City to attend City College of New York, graduating in 1945, and New York University School of Law, receiving his law degree in 1948. Koch was a sole practitioner from 1949 to 1964, and a partner with Koch, Lankenau, Schwartz & Kovner from 1965 to 1968. A Democrat, he became active in New York City politics as a reformer and opponent of Carmine DeSapio and Tammany Hall. In 1962 Koch ran for office for the first time, unsuccessfully opposing incumbent William Passannante, a DeSapio ally, for the Democratic nomination for the State Assembly.

In 1963, Koch defeated DeSapio for the position of Democratic Party leader for the district which included Greenwich Village, and Koch won again in a 1965 rematch. Koch served on the New York City Council from 1967 to 1969.