Currently 19 year old Dane Caroline Wozniacki.
Victoria Azarenka is currently ranked number one 9/9/12.
Currently, the number one women's player is Caroline Wozniacki and the number one Men's player is Rafael Nadal.
Currently the number one men's tennis champion is Novak Djokavic.
Novak Djokovic is the number one male player in the world. 49-1 this year!
As of January 19, 2014, the number one tennis player in the ATP is Rafael Nadal.
Tennis is one of those sports that is suited to both men AND women, so technically yes it is!