Mark Peter Kellar (born July 17, 1952) is a former American football running back who played three seasons with the Minnesota Vikings of the National Football League. He was drafted by the Minnesota Vikings in the sixth round of the 1974 NFL Draft. He played college football at Northern Illinois University and attended Irving Crown High School in Carpentersville, Illinois. Kellar was also a member of the Chicago Fire, Chicago Winds and San Antonio Wings of the World Football League.