Jon C. Olsen (born April 25, 1969) is an American former competition swimmer, four-time Olympic champion, and former world record-holder.

At the 1992 Summer Olympics in Barcelona, Spain, he won his first gold medal as a member of the winning U.S. team in the men's 4×100-meter freestyle relay, together with teammates Joe Hudepohl, Matt Biondi and Tom Jager.

He won a second gold medal for swimming the freestyle anchor leg for the first-place U.S. team in the men's 4×100-meter medley relay.

With his medley relay teammates Jeff Rouse (backstroke), Nelson Diebel (breaststroke), and Pablo Morales (butterfly), he tied the world record in the event of 3:36.93.

[1] Four years later at the 1996 Summer Olympics in Atlanta, Georgia, Olsen again won a gold medal as a member of the first-place U.S. team in the men's 4×100-meter freestyle relay with fellow team members Josh Davis, Brad Schumacher and Gary Hall, Jr., and set a new Olympic record of 3:15.41.