Leonard Charles "Cal" Lepore (April 15, 1919 – December 7, 2002)[1][2] was an American football head linesman, line judge and referee.

He worked as the line judge in Super Bowl III, won by the New York Jets over the Baltimore Colts, after the 1968 season.

Lepore is credited with promulgating the use of instant replay[4] as an officiating tool, as well as urging the use of coaches' challenges in professional football.

The NFL adopted nearly all of the components of the Replay Rule he authored and first administered in mid-1980s in the USFL.

He then played professional baseball;[6] his 1940 draft registration card listed his employer as the Chicago White Sox,[2] and Baseball-Reference.com has record of him playing for the minor league Jonesboro White Sox during the 1941 season as a second baseman.