Why Penny's Mom Susan From The Big Bang Theory Looks So Familiar

"The Big Bang Theory" is a show filled with recurring references to an inner mythology as dense and sprawling as that of your average epic fantasy saga. Although it always kept itself wholly accessible and enjoyable for first timers on an episode-to-episode basis — you don't get to double-digit ratings without that kind of viewer-friendliness, after all — the CBS flagship sitcom was also known to reward the fidelity and devotion of its leagues of fans. And one of the many running jokes of "The Big Bang Theory" is the fact that the audience never learns Penny's (Kaley Cuoco) official last name — not even when her family comes to town for her second wedding to Leonard (Johnny Galecki).

The visit in question happens on "The Conjugal Conjecture," the premiere episode of Season 10, in which Penny and Leonard hold a new wedding ceremony in order to include Leonard's mother Beverly (Christine Baranski) as well as Penny's own family. Although Penny's last name remains a well-kept secret by the end of the episode, "The Conjugal Conjecture" does stand out as the "Big Bang Theory" episode that finally allows viewers a more substantial glimpse into the background of its female lead. And one of the people we get to meet after nine seasons' worth of buildup is Penny's mother, Susan. In a sly bit of meta-casting, Susan is played by Katey Sagal, a veteran of the small screen who previously played Cuoco's mom on another sitcom, in addition to numerous roles you may have seen.

Katey Sagal is one of the most prolific television actors of her generation – a name that has been headlining hit television series for more than three decades. Incidentally, that's something she has in common with another industry veteran who broke out right by her side: Ed O'Neill, who, along with Sagal, led the landmark Fox comedy series "Married... with Children" for 11 years.

The show, which originally premiered in 1987, broke new ground in a lot of ways. Firstly, of course, because it was one of the very first scripted offerings of the then-freshman network Fox, and the show's enduring, decade-long success contributed significantly to propelling the network into the American TV big leagues. But, even setting aside that historical tidbit, "Married... with Children" also changed the game with the way it turned the established template of the family sitcom on its head. Dark, cynical, and laced with sour humor, the show became known for presenting nuclear family life as a waking nightmare, and Katey Sagal played a crucial part in that bold gambit with her fearlessly abrasive performance as Margaret "Peggy" Bundy — the vain, materialistic matriarch of the Bundy family.

For 11 seasons, true to the series' spirit, Peggy steadfastly refused to learn, grow, take up housewife chores, or get a job. She never stopped being her own incorrigible self, and Sagal never failed to do justice to the character as an authoritative ambassador for rule-breaking, formula-shredding comedy.

It's no coincidence that an actress as high-profile as Katey Sagal was cast in the relatively minor part of Penny's mom on "The Conjugal Conjecture." As a matter of fact, Sagal's presence is a casting gag in reference to the fact that Sagal and Kaley Cuoco previously played mother and daughter on a different 2000s sitcom — ABC's "8 Simple Rules."

Created by Tracy Gamble, "8 Simple Rules" was based on the best-selling book "8 Simple Rules for Dating My Teenage Daughter" by W. Bruce Cameron. In Season 1, the show follows the life of a family that goes through a significant shift in dynamics when the mother, Cate S. Hennessy (Sagal), begins to work a full-time job as a nurse, leaving her husband Paul (John Ritter) to take up the duties of an ultra-strict stay-at-home dad. Seasons 2 and 3 then pivot to a greater focus on Cate and the challenges she faces as a working mother after Paul dies offscreen, a narrative shift brought about by the untimely passing of John Ritter.

Throughout the entirety of "8 Simple Rules," but especially from Season 2 onward, the dynamic between Sagal's Cate and eldest daughter Bridget Erin "Beach" Hennessy, played by Cuoco, was central to both the show's humor and its pathos. Therefore, for fans of the ABC sitcom who tuned into Sagal's "Big Bang Theory" gig, the rapport between both actresses was already laden with plenty of emotional baggage.

Other than "Married... with Children," which rightfully established her as a TV legend, the most notable role of Katey Sagal's career is arguably Gemma Teller Morrow on FX's "Sons of Anarchy." Sagal played the Sons of Anarchy Motorcycle Club Redwood Original matriarch, widow of founding member John Teller (voiced by Nicholas Guest), mother of series protagonist Jax (Charlie Hunnam), and wife of current president Clay Morrow (Ron Perlman) on every single one of the show's 92 episodes between 2008 and 2014, ultimately going down as one of the most iconic TV co-leading performances of the 21st century so far.

If "Sons of Anarchy" as a whole could be read as a very out-there, modernized reimagining of William Shakespeare's "Hamlet," Gemma would be something like the show's own Gertrude – the scheming, intractable queen mother (in this case, of Charming, California, rather than Denmark) who will go to any lengths necessary to protect her family and its legacy. For Sagal, who was previously primarily known for her comedic roles, Gemma provided an opportunity and a challenge to demonstrate just what she was capable of dramatically. The intensity, complexity, ruthless intelligence, and sheer presence with which she embodied the queen of Charming earned her the most glowing notes of her career, as well as a multitude of awards including a Golden Globe win for best performance by an actress in a drama series in 2011.

Following the end of "Sons of Anarchy" in 2014, Katey Sagal made a number of appearances on TV shows both comedic and dramatic, including teaming up with "Sons of Anarchy" creator Kurt Sutter again for a regular role as Annora of the Alders on FX's short-lived "The Bastard Executioner," guest starring on "Brooklyn Nine-Nine" as Jake Peralta's (Andy Samberg) mother Karen, and playing Gemma Teller Morrow again on an episode of "Mayans M.C.," not to mention her "The Big Bang Theory" spot.

In addition to those projects, Sagal had substantial roles on both "Shameless" and "Dead to Me." On "Shameless," she played Dr. Ingrid Jones, the psychotherapist whom Frank Gallagher (William H. Macy) meets at a hospital and falls in love with over the course of Season 9. Their relationship develops to the point where Ingrid convinces Frank to donate his sperm to fertilize her frozen eggs, but it goes south when Frank finds that he is infertile and tries to come up with a fix that only makes things worse, as tends to be his modus operandi. On "Dead to Me," meanwhile, Sagal played Judy Hale's (Linda Cardellini) abusive mother, Eleanor.

The post-"Sons of Anarchy" period also saw Katey Sagal headline a TV series all of her own, the ABC legal dramedy "Rebel," on which she played Annie "Rebel" Bello, a legal advocate loosely based on Erin Brockovich. The series was ultimately canceled after airing a single 10-episode season in 2021.

The marriage of Roseanne Conner (Roseanne Barr) and Dan Conner (John Goodman) was definitional for television in the 1990s; theirs was the kind of warm, relatable sitcom family that became almost like a second clan to the millions upon millions of "Roseanne" viewers. So, when it came time for "The Conners" to replace the "Roseanne" reboot and tread a new narrative path that inevitably deals with the death of Roseanne Conner, one of its toughest challenges was to depict the way that Dan dealt with it without straying from the show's basically good-natured and comforting slant.

John Goodman, as ever, proved up to the task, continuing to make Dan dependably lovable and hilarious even while deep in mourning. And, in rendering this new era for Dan, he has been aided by Katey Sagal, who took up the initially guest-starring, now recurring role of Dan's former high school friend and new love interest Louise Goldufski, who marries him in Season 4 and becomes Louise Goldufski-Conner. Much like her "The Big Bang Theory" casting as Kaley Cuoco's newest sitcom mom, Sagal's casting on "Roseanne" is a bit of a meta-gag as, per Vulture, Roseanne Barr was originally offered the role of Peggy Bundy before Sagal, yet ended up turning it down, opening up the path for both actresses to each embark on life-changing, legendary working-class family sitcom roles of their own. Dan sure has a type.