Jan Kodeš (born 1 March 1946) is a Czech former professional tennis player. A three-time major singles champion, Kodeš was one of the premier players in the early 1970s.
Kodeš's greatest success was achieved on the clay courts of the French Open. He won the singles title in 1970 French Open beating Željko Franulović in straight sets in the final. He won the 1971 French Open over Ilie Năstase in the final in four sets, his "tireless running and gifted anticipation" proving too much for the Romanian. He also won Wimbledon on grass courts in 1973, beating Alex Metreveli in the final in straight sets, although the tournament was largely boycotted by top players that year in a show of solidarity over the ban of Nikola Pilić by the International Lawn Tennis Federation (ILTF).
Kodeš never played at the Australian Open, but was twice the runner-up at the US Open, in 1971 to Stan Smith and 1973 to John Newcombe.