Known for playing David Healy in the sitcom Roseanne, and Leonard Hofstadter in the comedy series The Big Bang Theory, Johnny Galecki is a Belgium-born American actor. He has featured in movies like A Night in the Life of Jimmy Reardon (1988), A Family Torn Apart (1993), I Know What You Did Last Summer (1997), and Vanilla Sky (2001).

Early Life
Born John Mark Galecki, to American parents, the actor’s father Richard Galecki, was a member of the U.S Air Force, stationed in Belgium, while his mother, Mary Lou was a mortgage consultant. The family shifted to their home country- U.S., when Galecki was just three. His father then became a teacher for blind veterans in a VA hospital outside of Chicago. By the time Galecki turned seven, he knew he wanted to become an actor and had started starring in productions at Chicago's Goodman Theater. Galecki has two younger siblings- a brother named Nick, who works in an automobile industry and a sister Allison. At the age of 16, Galecki suffered a great loss, when his father passed away in an accident.

Personal Life
Galecki dated his TBBT co-star Kaley Cuoco for two years. The couple met on the sets of the show, but parted ways, just two years later. Cupid struck once again, in 2012, when he began a relationship with actress Kelli Garner. Unfortunately, the couple announced their separation in 2014.

Movie Career
After making a small appearance in William Richert’s coming-of-age drama film A Night in the Life of Jimmy Reardon, Galecki went on to feature in movies like Prancer (1989) and National Lampoon's Christmas Vacation (1989). In 1997, he starred alongside Sean Patrick Flanery, Jeremy Sisto, and Henry Thomas in the action comedy film Suicide Kings. Directed by Peter O'Fallon, the movie failed miserably at the box office. The same year, he starred in the commercial blockbuster I Know What You Did Last Summer. Co-starring Jennifer Love Hewitt, Sarah Michelle Gellar, Ryan Phillippe and Freddie Prinze, Jr., with Anne Heche, and Bridgette Wilson, the movie was a slasher film directed by Jim Gillespie. Galecki, subsequently starred as Seth, in the romantic drama film Bounce, featuring Ben Affleck and Gwyneth Paltrow in the lead. In the coming years, he appeared in films like Vanilla Sky (2001), Happy Endings (2005), and Table for Three (2009). His 2017 release includes the supernatural horror film Rings, which is the third film in the American Ring franchise; first two being The Ring (2002) and The Ring Two (2005).

Television Career
In 1992, Galecki was roped in for the top television show at that time Roseanne. Initially cast only for one season, his portrayal of David Healy, received so much love and appreciation, that the producers decided to keep him on the show for the next five seasons. In 1994, he took home the Young Artist Award- Best Youth Comedian, for Roseanne.

He then played Dr. Leonard Hofstadter on the American TV sitcom The Big Bang Theory. For his character of an experimental physicist, Galecki received Primetime Emmy and Golden Globe nominations. His other television credits include shows like American Dreamer (1990-1991), Billy (1992), and Entourage (2011).