L.L. Cool J turns 45 years old today!

It's hard to believe that the "NCIS: Los Angeles" star was once a radio regular -- who can forget his 1990's hit, "Mamma Said Knock You Out"?

L.L. became one of the most famous faces of rap, and his songs helped shape an entire generation of artists and music lovers alike.

He's definitely talented -- the "Going Back to Cali" singer has moved from the airwaves to the big screen, starring in flicks like "Charlie's Angels," "Any Given Sunday" and "S.W.A.T."

Mr. Cool J tied the knot with Simone Johnson in 1995 and the pair share four children together. While we love seeing L.L kick the bad guy's butt on the small screen, we do miss his gold chains and sans shirt days!

To see more musicians of the '90s click "Launch Gallery" above!