Ralph Thomas Walker FAIA (November 28, 1889 – January 17, 1973) was an American architect, president of the American Institute of Architects and partner of the firm McKenzie, Voorhees, Gmelin; and its successor firms Voorhees, Gmelin & Walker, Voorhees, Walker, Foley & Smith; Voorhees, Walker, Smith & Smith; and Voorhees, Walker, Smith, Smith & Haines. Walker is best known for his designs for the Barclay–Vesey Building (1922–26) and 1 Wall Street (1928–31), but was also involved in numerous other Art Deco telecommunications buildings in the New York City area.