#15 Billie Jean King
Not only is Billie Jean King one of the world’s most formidable tennis players of all time, but she was also an early advocate for LGBT rights in the United States. Furthermore, she was a leader in the movement for athletes to be paid fairly.
After admitting to a secret affair in 1971 with a previous secretary, King became one of the first celebrities to come out as a lesbian, though she remained married to Larry King for another decade. She’s the holder of 39 Grand Slam titles—12 singles, 16 doubles, and 11 mixed.