Happy Birthday, Serena Williams!.
Serena Jameka Williams turns 40 years old today.
Here are five fun facts about the tennis superstar.
She has been playing tennis since she was just 3 years old.
Aside from tennis, her favorite sport to watch is gymnastics.
The "Serena Slam" tennis term is used when someone wins all four Grand Slams in a row.
Williams has served over 120 mph.
She has won 23 Grand Slams. Happy Birthday, Serena Williams!