Jelena Jankoviæ (born February 28, 1985) is a Serbian professional female tennis player. She was the year-end No. 1 in 2008. Jankovic is the only No. 1 tennis player who has not yet won a singles Grand Slam title.

Jankoviæ has reached the singles final of the US Open and the singles semifinals of the Australian Open and the French Open. In 2007, she won the Wimbledon mixed doubles title with British partner Jamie Murray.