Donald Roy Johnson (November 12, 1926 – February 10, 2015) was an American Major League Baseball pitcher.

The 6 ft 3 in (1.91 m), 200 lb (91 kg) right-hander was signed by the New York Yankees before the 1944 season and played for the Yankees (1947, 1950), St. Louis Browns (1950–51), Washington Senators (1951–52), Chicago White Sox (1954), Baltimore Orioles (1955), and San Francisco Giants (1958).

Johnson made his major league debut on April 20, 1947, starting game 2 of a doubleheader against the Philadelphia Athletics at Shibe Park.

He won 8, lost 7, had a 3.12 earned run average, and finished in the American League Top ten in games pitched, saves, and shutouts.

Johnson led the International League with 156 strikeouts and a 2.67 ERA while playing for the Toronto Maple Leafs in 1953.