Otto Hamlin "Jack" Saltzgaver (January 23, 1903 – February 1, 1978) was an American professional baseball player.

The native of Croton, Iowa, as an infielder, appeared in 278 Major League Baseball games for the New York Yankees (1932; 1934–1937) and the Pittsburgh Pirates (1945).

Saltzgaver batted left-handed, threw right-handed, stood 5 feet 11 inches (180 cm) tall and weighed 165 pounds (75 kg; 11.8 st).

The following year, he was supplanted by Red Rolfe as the Yanks' starter at the hot corner.

At the time he played for the Pirates, during the last season of the World War II manpower shortage, the 42-year-old Saltzgaver was the oldest active Major League player.