Johnny Mark Galecki was born on April 30, 1975 in Bree, Belgium where his father was a member of the US Air Force and at age three, their family moved to Chicago. His first major role was as Kevin Healy in the sitcom Roseanne and thereafter he started landing roles such as Max Neurick on I Know What You Did Last Summer and Jason Bock on The Opposite of Sex, where he played a gay man who pretends to be molested by another man. He again took the role of a gay man, Seth on Bounce in 2000. His other film appearances include those in Vanilla Sky and Bean. He graced television screens through his appearances on Hope & Faith, My Name is Earl and My Boys. In 2007, Galecki was cast as Leonard on the CBS series The Big Bang Theory.

Leonard is played by Johnny Galecki on the television series The Big Bang Theory. Leonard is a physicist who knows little about life until he meets an attractive woman in the form of his pretty new neighbor, Penny to teach him and his best friend what they're really missing outside their laboratory.



(Photo courtesy of CBS)