David Owen Williams (July 1879 – April 25, 1918) was an American relief pitcher in Major League Baseball who played briefly for the Boston Americans during the 1902 season.

Listed at 5 ft 11.5 in (1.82 m), 167 pounds (76 kg) Williams batted right-handed and threw left-handed.

In his three-game MLB career, Williams posted a 5.30 earned run average in 18+2⁄3 innings of work, including seven strikeouts, 11 walks, three games finished, and 22 hits allowed without a decision.

There, he was teammates with future Baseball Hall of Famer Christy Mathewson.

Williams taught Mathewson how to throw the "fadeaway" pitch, later known as the screwball.