who plays leonards dad on big bang theory
Judd Hirsch In 2016 Hirsch appeared on the CBS comedy series The Big Bang Theory portraying Leonard's (Johnny Galecki) father.
Johnny Galecki John Mark Galecki (born April 30, 1975)[1] is an American actor. He is known for playing Leonard Hofstadter in the CBS sitcom The Big Bang Theory (2007–present) and David Healy in the ABC sitcom Roseanne (1992–1997; 2018). Galecki also appeared in the films National Lampoon's Christmas Vacation (1989), Prancer (1989), Suicide Kings (1997), I Know What You Did Last Summer (1997), Bookies (2003), In Time (2011), and Rings (2017).