‘The Big Bang Theory’ Casts Katey Sagal as Penny’s Mom — Find Out Who Will Play Penny’s Brother!

They're a mother-daughter pair — again! Katey Sagal is joining the cast of The Big Bang Theory as the mom of Penny (Kaley Cuoco), with the CBS comedy's writers announcing the news at San Diego Comic-Con on Friday, July 22.

The team revealed during their panel that the Sons of Anarchy alum, 62, will appear in the season 10 premiere this fall as Susan, who lives in Omaha, Nebraska, and thus far has never appeared on the show.

The casting pick reteams the two actresses, who worked together on the sitcom 8 Simple Rules for Dating My Teenage Daughter. Sagal also played Cuoco's mom on that show, which signed off after three seasons in May 2005. (The late John Ritter played the family patriarch.)

Also appearing for the first time in the season 10 premiere is Penny's brother, Randall, played by Jack McBrayer. Randall is a drug dealer who has been released from prison in time to attend Leonard (Johnny Galecki) and Penny's redo wedding ceremony.

The Big Bang Theory
'The Big Bang Theory' Monty Brinton/CBS

McBrayer — who earned an Emmy nomination for his role as Kenneth on 30 Rock — made a surprise appearance during the panel, where the writers jokingly asked him if he's ever been to prison. "Recreationally," the actor, 43, replied.

Speculation has run rampant that season 10 might be the Emmy-winning comedy's final season, as both showrunner Steven Molaro and Kunal Nayyar (Raj) recently hinted that this could be the case. But the writers declined to comment during Friday's panel about when the series might end.

Katey Sagal
Katey Sagal will play Kaley Cuoco's mom on 'The Big Bang Theory.' Mark Davis/WireImage

Season 9 saw the arrival of another one of the core characters' parents, as Judd Hirsch was introduced as Leonard's father, Alfred, in the season's final episode.

Tell Us: Is Sagal a good fit to play Penny's mom?

The Big Bang Theory returns to CBS Monday, September 19, at 8 p.m. ET. 

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