Kim Clijsters is putting down the racket for good -- again -- the tennis superstar just announced she's retiring from the sport for the third time to focus on her family.
The 38-year-old former #1 overall player in the world broke the news via Instagram on Tuesday ... saying, "I want to share with you that I have decided to no longer play official tournaments."
This will be the third time the Belgian player has retired -- in 2007, she left to marry former basketball player Brian Lynch.