Keith Lieppman (born January 17, 1949) is an American front office executive in Major League Baseball. In , he began his 19th consecutive season as the director of player development of the Oakland Athletics — his 40th consecutive season in the Oakland organization as a minor league first- and third baseman and manager, and Major League farm system official. Lieppman thus has been a member of the Athletics' system during the Charlie Finley dynasty of the 1970s, the Sandy Alderson/Tony LaRussa teams of the late 1980s, and the Billy Beane-led organization of the 21st century.
As a player, Lieppman batted and threw right-handed, stood 6 feet 2 inches (1.9 m) tall and weighed 205 pounds (93 kg). After attending the University of Kansas, he was drafted as an amateur in the second round by Oakland in , and played nine seasons in their farm system, including all or parts of six seasons at the Triple-A level. In his best season, 1974 with the Tucson Toros of the Pacific Coast League, he batted .321 in 346 at bats.
In , he became a manager in the Oakland farm system and worked at all levels of their organization, culminating with three years (1985-87) as pilot of the Tacoma Tigers of the PCL, then the Athletics' top affiliate. He then served as the Oakland organization's director of instruction for four years (1988-91) before succeeding Walt Jocketty as the Athletics' director of player development in .