Joseph Zaretzki (March 9, 1900 - December 20, 1981) was an American lawyer and politician from New York. He was Majority Leader of the New York State Senate in 1965, the only Democrat in this position since the adoption of the New York State Constitution of 1938 until Malcolm Smith attained the position in 2009.
He was born on March 9, 1900, in New York City. He served in the United States Army during World War I.
In November 1947, he was elected to the New York State Senate, to fill the vacancy caused by the appointment of Alexander A. Falk as Civil Service Commissioner. Zaretzki represented the Washington Heights area of Manhattan from 1948 to 1974, sitting in the 166th, 167th, 168th, 169th, 170th, 171st, 172nd, 173rd, 174th, 175th, 176th, 177th, 178th, 179th and 180th New York State Legislatures. He was the Democratic Minority Leader from 1957 to 1964, and from 1966 to 1974.