About
Johnny Galecki is an American actor known for his prominent roles in television. He achieved widespread recognition for his portrayal of Leonard Hofstadter on the hit CBS sitcom The Big Bang Theory. Prior to that, he was recognized for playing David Healy in Roseanne. Galecki has also appeared in several films, including National Lampoon's Christmas Vacation, I Know What You Did Last Summer, and In Time.
Career Timeline
"Christmas Vacation" role
Early role in Christmas Vacation provides initial exposure and sets the stage for future work.
"Roseanne" breakthrough
His role as David Healy in Roseanne establishes him as a recognizable face in television comedy.
"Big Bang Theory" success
His role as Leonard Hofstadter in The Big Bang Theory catapults him to international fame and massive financial success.
Big Bang Theory ends
The Big Bang Theory concludes after 12 seasons, solidifying his status as a major comedic actor and providing significant financial security.
Continued Career
Galecki continues to be successful, investing in real estate and other ventures.
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Last updated: February 24, 2026