Zack Johnson[1] is an on-and-off boyfriend of Penny's who first appeared in "The Lunar Excitation" (S03E23). He and Penny once got married on a whim while in Las Vegas; Both Zack and Penny were unaware it was a real wedding and ended up having it annulled later. Though usually a friendly, outgoing person, Zack is extremely dimwitted and displays even less understanding of sarcasm than Sheldon does. Despite his stupidity, he is quite interested in science.

He is a literary foil, juxtaposed to Leonard, and perhaps to a lesser degree Kurt, Penny's 'jock douche-bag' ex-boyfriend. Zack is always friendly, non-aggressive, and arguably even less intelligent than Kurt. He is in between Leonard and Kurt in all perceivable aspects; he has a fairly remedial and unremarkable career (unlike Leonard), but has no mentioned criminal record (unlike Kurt). Zack also appears to be weaker than Kurt, but the same height as Kurt as well as tougher than an average person. He is presented as moderately attractive.

Character Information

Zack, as well as his sister, is the Vice President of the company that designs the Cheesecake Factory's menus (as well as other restaurant's menus) which is owned by his father and which is how he met Penny. In "The Lunar Excitation" (S03E23), he goes on a date with Penny who, allegedly due to having dated Leonard, finds his stupidity insufferable and winds up having a drunken sexual encounter with Leonard on the same night.

Zack makes a second appearance in "The Alien Parasite Hypothesis" (S04E10). He briefly meets Amy Farrah Fowler, who instantly feels sexually attracted towards him. She later approaches him at a bar hoping for sexual intercourse with him, but his stupidity becomes too much of a turnoff for her to go through with it. When they shake hands, Amy whimpers, saying that "should hold [her] over" for a while. Then, Amy says "Hoo".

Penny gets back together with Zack again in "The Justice League Recombination" (S04E11), later admitting to Leonard that she only did so in order not to be alone on New Year's Eve. In this episode Zack attempts to befriend Leonard, Sheldon, Raj and Howard. He dresses up as Superman for Stuart's New Year's party, helping them complete their Justice League theme and win the contest for best group costume. He and Penny apparently broke up again sometime afterwards.

TBBT 417

Stuart, Kripke and Zack singing "Walking On Sunshine".

Zack appears again in "The Toast Derivation" (S04E17), having been invited to Sheldon and Leonard's apartment by Sheldon. This gathering is Sheldon's attempt to establish a new social group, along with Kripke, Stuart, and hopefully LeVar Burton, after Sheldon got angry because he was not the center of his previous social group. At the social event, Zack impresses Stuart and Kripke with his tale of a naked woman in a hot tub, and later the three end up singing karaoke, much to Sheldon's dismay.


The return of Zack Johnson.

In "The Thanksgiving Decoupling" (S07E09), Penny mentions the fake wedding ceremony she and Zack went through on a Thanksgiving trip to Las Vegas three years ago. Leonard, Sheldon and Amy explain that those wedding chapels are real and that Penny is legally married to Zack, who also thought the ceremonies were fake. Penny realizes that she is married and is Mrs. Zack Johnson. While dinner is being prepared, Penny has annulment papers downloaded, fills them out and calls Zack over to sign them. Dense as ever, Zack wonders if he should do it to their kids. Penny reminds him that they have no children and he asks if she's sure about that, since she didn't even know she was really married to him. He signs it and they all sit down to a Thanksgiving dinner.

In "The Cooper Extraction" (S07E11), Leonard makes up a story about what if Penny would have ended up with Zack. Leonard imagines that Zack would use the money for rent to buy magic beans, and then Zack and Penny would both pee their pants.

In "The Fermentation Bifurcation" (S9E22), Penny, Leonard, Howard, Raj and Amy see him again at the wine-tasting house and he takes an interest in Raj's newest companion, Claire. Raj sets him straight. Also, Zack wonders if the guidance system the guys are developing could be use by the military for war causing the guys worries. He also admits that he has always liked Leonard and Penny together, especially after seeing that they got married.

In "The Cognition Regeneration" (S10E22), Zack offered Penny a job, which makes Leonard less than thrilled because of the fact that it would be weird for exes to work together. Zack also announces that he has gotten engaged and that his fiancé doesn't want him working with Penny so no job.

In "The Bitcoin Entanglement" (S11E09), Leonard and Penny visit him to reclaim Leonard's old laptop that Penny had given him years ago. Zack also shows them an old video a drunk Penny made after she broke up with Leonard seven years before. She did love him, but was scared of a permanent commitment.

He will be appearing in "The Propagation Proposition" (S12E12). He is revealed to be married again, but this time to a woman named Marissa.



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  1. Full name first revealed by Sheldon in The Alien Parasite Hypothesis (S04E10)


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The Big Bang Theory Characters, Cast & Crew
Characters Main Leonard Hofstadter  ‧  Sheldon Cooper  ‧  Penny Hofstadter  ‧  Howard Wolowitz  ‧  Rajesh Koothrappali  ‧  Amy Farrah Fowler  ‧  Bernadette Rostenkowski-Wolowitz  ‧  Stuart Bloom  ‧  Emily Sweeney   ‧  Leslie Winkle    The Social Group
Recurring/Minor Debbie Wolowitz  ‧  Barry Kripke  ‧  Priya Koothrappali  ‧  Dr. V. M. Koothrappali  ‧  Mrs. Koothrappali  ‧  Stephanie Barnett  ‧  Lucy  ‧  Mary Cooper  ‧  Zack Johnson  ‧  Beverly Hofstadter  ‧  Mike Rostenkowski  ‧  Alex Jensen  ‧  Professor Proton  ‧  Missy Cooper  ‧  Ramona Nowitzki  ‧  Dan  ‧  Josh Wolowitz  ‧  Dennis Kim  ‧  Althea Davis  ‧  Jeanie  ‧  Cinnamon  ‧  Mrs. Rostenkowski  ‧  Wyatt  ‧  Claire  ‧  Kurt  ‧  Eric Gablehauser  ‧  Dave Gibbs  ‧  Dimitri  ‧  Alfred Hofstadter   ‧  Meemaw  ‧  Susan  ‧  Randall  ‧  Bert Kibbler  ‧  President Siebert  ‧  Janine Davis  ‧  Colonel Richard Williams  ‧  Halley Wolowitz  ‧  Neil Michael Wolowitz  ‧  Denise  ‧ George Cooper Jr.  ‧  Larry Fowler
Cast Regulars Johnny Galecki  ‧  Jim Parsons  ‧  Kaley Cuoco  ‧  Simon Helberg  ‧  Kunal Nayyar  ‧  Mayim Bialik  ‧  Melissa Rauch  ‧  Kevin Sussman  ‧  Laura Spencer  ‧  Sara Gilbert  ‧ 
Recurring/Minor Christine Baranski  ‧  Aarti Mann  ‧  John Ross Bowie  ‧  Casey Sander  ‧  Stephen Merchant  ‧  Sara Rue  ‧  Kara Luiz  ‧  Brian Thomas Smith  ‧  Margo Harshman  ‧  Alessandra Torresani  ‧  Matt Bennett  ‧  Keith Carradine  ‧  Laurie Metcalf  ‧  Judd Hirsch  ‧  Carol Ann Susi  ‧  Meagen Fay  ‧  Brian George  ‧  Alice Amter  ‧  Courtney Henggeler  ‧  June Squibb  ‧  Katey Sagal  ‧  Jack McBrayer  ‧  Dean Norris  ‧  Brian Posehn  ‧  Mark Harelik  ‧  Joshua Malina  ‧  Brian Patrick Wade  ‧  Kate Micucci  ‧  Regina King  ‧  Jerry O'Connell
As Selves Wil Wheaton  ‧  Mike Massimino  ‧  Stephen Hawking  ‧  Katee Sackhoff  ‧ Steve Wozniak  ‧ Buzz Aldrin  ‧ Summer Glau  ‧ James Earl Jones  ‧ Carrie Fisher  ‧ Brent Spiner  ‧ Howie Mandel  ‧ Bill Nye  ‧ George Smoot  ‧ George Takei  ‧ LeVar Burton  ‧ Neil deGrasse Tyson  ‧ Brian Greene  ‧ Charlie Sheen  ‧ Stan Lee  ‧ Adam West
Crew Writers Chuck Lorre * (Creator)  ‧  Bill Prady * (Creator)  ‧  Steven Molaro *  ‧  Steve Holland *  ‧  Maria Ferrari *  ‧  Jim Reynolds *  ‧  Eric Kaplan *  ‧  Anthony Del Broccolo  ‧  Lee Aronsohn *  ‧  Dave Goetsch *  ‧  Tara Hernandez  ‧  Richard Rosenstock *
Directors Mark Cendrowski  ‧  Peter Chakos * (mainly as Editor)  ‧  Anthony Rich  ‧  James Burrows
Science consultant : David Saltzberg Director of photography : Steven V. Silver
Costume designer : Mary T. Quigley * Unit production manager : Kelly-Anne Lee *
Theme composer / performer : Barenaked Ladies Chuck Lorre Productions
also as Producer The Big Bang Theory : Full cast & crew on IMDb