One simple rule for the perfect reunion as Katey Sagal signs up as Kaley Cuoco's mum on The Big Bang Theory


Katey Sagal and Kaley Cuoco will be reuniting as TV mother and daughter on The Big Bang Theory, 11 years after they last starred together.

Sons of Anarchy star Katey has been been cast as Susan, the mother of Kaley's character Penny, in the upcoming series 10 of the hit US sitcom, it was revealed by executive producer Steve Molaro at the show's Comic-Con panel on Friday.

Katey Sagal is joining The Big Bang Theory (David Crotty/AP/PA)

It is a reunion a long-time in the making as the pair last starred together as Cate and Bridget Hennessy on comedy 8 Simple Rules, which ran from 2002 to 2005.

Kaley shared her delight at the news on Instagram with a picture of the pair, writing, "Yes yes yes yes !!! Once my tv mom, always my tv mom. Love you @kateylous !!!!! #fullcircle"

30 Rock's Jack McBrayer has been cast as Penny's brother Randall and Steve confirmed both will appear in the season premiere.

Penny's family have been mentioned frequently throughout the show, but only her father, played by Keith Carradine, has ever been seen.

Jack McBrayer will join as Penny's brother (Andreas Branch/AP/PA)

Kaley's character Penny married boyfriend Leonard Hofstadter, played by Johnny Galecki, at the beginning of series nine and the final episode saw them hold a second wedding ceremony without Penny's family present.