The 10 Best Johnny Galecki Movies and TV Shows Ever: From ‘Roseanne’ to ‘The Big Bang Theory’

Johnny Galecki wasn’t content to wait on an acting career. Born in Bree, Belgium, on April 30, 1975 to U.S. Air Force officer Richard Galecki and wife Mary Lou, the family moved to Chicago when he was three years old. Siblings Allison (1980) and Nick (1982) soon followed.

He was determined to get started in showbiz at a young age. “I started talking about it when I was 3, and I have no idea how the word ‘actor’ was even in my vocabulary,” he told Variety in 2018. “No one in my immediate family was an actor, or even in theater or television. We barely had money to go to the movies, let alone buy a theater seat, so it wasn’t part of my family’s lifestyle, and it was just my answer when people asked, ‘What do you want to be when you grow up?’ I really have no idea how I came upon that, but I feel incredibly blessed that that was the case, because I see people, even in their 30s and 40s, struggling to learn what their calling is, and I think I just knew it as soon as I could speak.”

He first appeared in the Chicago production of Fiddler On The Roof, and received a Joseph Jefferson Citation nomination for playing John Henry in The Member of the Wedding at age 11.

Galecki kicked off his screen career with the family TV movie Time Out For Dad (1987), romantic comedy A Night In The Life of Jimmy Reardon (1988) and holiday family drama Prancer (1989) before enjoying the success of a major hit with the Christmas classic, National Lampoon’s Christmas Vacation (1989).

“It’s not terrifying when you’re 7,” he told Variety. “It’s terrifying when you’re 27. The stakes aren’t that high when you’re 7 years old. You can always go back to Little League.”

He joined the cast of Roseanne (1988-1997; 2018-2019) in 1992.

Galecki appeared in crime comedy Suicide Kings (1997), horror film I Know What You Did Last Summer (1997), romantic comedy The Opposite of Sex (1998), comedy Playing Mona Lisa (2000), romantic drama Bounce (2000)  and mystery Vanilla Sky (2001) before landing his biggest role: Outgoing nerd Leonard on the brainy television romantic comedy The Big Bang Theory (2007-2019).