The 1903 United States Senate election in New York was held on January 20, 1903, by the New York State Legislature to elect a U.S. Senator to represent the State of New York in the United States Senate.

Thomas Collier Platt, also known as Tom Platt and Easy Boss, was an American politician who was a two-term member of the U.S. House of Representatives (1873–1877) and a three-term U.S. Senator from New York in 1881 and 1897 to 1909. He is best known as the "political boss" of the Republican Party in New York State in the late 19th century and early 20th century. Upon his death, the New York Times stated that "no man ever exercised less influence in the Senate or the House of Representatives than he," but "no man ever exercised more power as a political leader." He considered himself the "political godfather" of many Republican governors of the state, including Theodore Roosevelt.