Irwin Delmore Davidson (January 2, 1906 – August 1, 1981) was an American lawyer, jurist, and politician who served one term as a Democratic-Liberal member of the United States House of Representatives from New York from 1955 to 1956.

Davidson was born on January 2, 1906, in New York City.

He was a member of the New York State Assembly in 1937.

He was elected to the 84th United States Congress, holding office from January 3, 1955, to December 31, 1956, when he resigned.

He died at his home at Premium Point in New Rochelle, New York on August 1, 1981.