Harley Park Parker (June 14, 1872 – March 3, 1941) was a pitcher in Major League Baseball who played from 1893 through 1901 for the Chicago Colts (1893, 1895–1896) and Cincinnati Reds (1901).

Listed at 6 ft 2 in (1.88 m), 200 pounds (91 kg), Parker threw and batted right-handed.

In a four-season career, Parker posted a 5–8 record with 24 strikeouts and a 5.90 ERA in 18 appearances, including 14 starts, 13 complete games, one shutout, one save, and 134+1⁄3 innings of work.

Parker was responsible for one of the worst pitching performances in Major League Baseball history.

This biographical article relating to an American baseball pitcher born in the 1870s is a stub.