Professionals in the business community in offices/workplaces who had to deal with the extremely bright scientists who frustrated them, especially Sheldon.
Michael Croner as Andre in The Solder Excursion Diversion who convinces Leonard and Howard to see the Wil Smith film preview.
Jim Holmes as Tim in The Application Deterioration who is the Caltech patent attorney the guys discuss patenting their discovery with.
Wayne Wilderson as Travis in The Platonic Permutation who ran the soup kitchen that the guys worked in on Thanksgiving Day.
Elena Campbell-Martinez as Maria as the Caltech maintenance worker who has been on three episodes.
Louise Claps as the Receptionist (Voice Only) The Matrimonial Momentum at the Las Vegas wedding chapel where Leonard and Penny got married.
Jim Meskimen as the Minister in The Matrimonial Momentum at the Las Vegas wedding chapel where Leonard and Penny got married.
Sara Erikson as Gwen in The Communication Deterioration was an actress Penny met at the "Clerks 3" auditions.
Kelli Goss as Chelsea in The Communication Deterioration was an actress Penny met at the "Clerks 3" auditions that knew Penny.
Phoebe Neidhardt as Casting Assistant in The Communication Deterioration was the casting director at the "Clerks 3" auditions.
Molly Morgan as Hostess in The Intimacy Acceleration was the escape room hostesses.
Max Adler as Zombie in The Intimacy Acceleration was the zombie that menaced the guys in the escape room.
Michael Reetz as Photographer in The Clean Room Infiltration who took Sheldon's picture on Santa's lap.
Malcolm Foster Smith as Roy in The First Pitch Insufficiency the Anaheim Angels' employee who helped Howard just before he threw out the first pitch.
Kaliko Kauahi as the Employee in The Gorilla Dissolution on the set of Serial Ape-ist 2: Monkey See, Monkey Kill.
Kimberly Herbert Gregory as Ms. Davon in The Anything Can Happen Recurrence who was the psychic that Penny took Sheldon to.
Rod Keller as Wardrobe Person in The Indecision Amalgamation on the set of "Serial Apeist 2".
Riccardo LeBron as Tom in The Monster Isolation who performed a scene from "A Streetcar Named Desire" with Penny in her acting class.
John Mendoza as Chauffeur in The Re-Entry Minimization who was waiting for Howie Mandel at the airport for Howard's flight.
Peter Onorati as Angelo in The Werewolf Transformation who is the nephew of Sheldon's regular barber.
Jim Turner as Reverend White in The Recombination Hypothesis who Penny envisions marrying her and Leonard when she is very pregnant.
Stacey Travis as Sandy in The Skank Reflex Analysis who is actress that Penny does the hemorrhage commercial with.
Arnold Chun as Ho-Jun in The Agreement Dissection as the taxi driver who took the girls to a dance club.
Eric Andre as Joey in The 21-Second Excitation who was managing the waiting line for the "Raiders of the Lost Ark" movie.
Ren Hanami as Singer in The Pants Alternative who is singing at Sheldon's award banquet.
Steve Paymer as Judge J. Kirby in The Excelsior Acquisition who tried Sheldon's traffic ticket court appearance.
Andy Mackenzie as Skeeter in The Gothowitz Deviation who was the tattoo artist.
Livia Trevino as Lourdes in The Euclid Alternative as the Caltech maintenance worker.
Sherry Weston as Instructor in The Fuzzy Boots Corollary as Howard's line dancing instructor.
D'Kia Anderson as the Hostess in The Monetary Insufficiency that Sheldon meets in a Las Vegas casino.
Eileen Galindo as Letty in The Gates Excitation as a Hispanic nanny that Stuart tries to talk to in pigeon Spanish.
Elka Rodriguez as the Rose lady in The Geology Methodology who tries to sell Raj a rose at a non-date.
Steve Valentine as Kenneth in The Gorilla Dissolution who the director of Penny's gorilla movie.
Laura Ceron as Marta in The Gates Excitation as a Hispanic nanny that Stuart tries to talk to in pigeon Spanish.
Michael Rapaport as Kenneth Fitzgerald in The Helium Insufficiency who sells Leonard and Sheldon some stolen helium.
James Maslow as Bartender in The Sibling Realignment as the bartender at Amy's bachelorette party.
Joel Murray as Doug in The Recollection Dissipation as the bartender at cowboy bar that Sheldon loses his notebook at.
Stephanie Escajeda as Cindy in The Intimacy Acceleration as the airline employee who can't find Mrs. Wolowitz's ashes.
Barak Hardley as Pizza Delivery Guy in The Deception Verification who delivers a pizza to Penny who is also hiding Leonard.
Josh Zuckerman as Marty in The Military Miniaturization who is Howard's lawyer cousin.
Maria Canals-Barrera as Issabella in The Brain Bowl Incubation who is a maintenance employee that works at Caltech and Raj takes an interest in.
Josh Peck as Jesse in The Occupation Recalibration who is a smart-alec that owns a rival comic book store.
Samantha Potter as Model in The Panty Piñata Polarization who lives at the model house that Howard and Raj tracked down.
Frank Maharajh as Venkatesh Koothrappali in The Precious Fragmentation as Raj's lawyer cousin.
Craig Duda as Delivery Man in The Big Bran Hypothesis.
Stephen Root as Dan in The Champagne Reflection and The Locomotion Interruption as Bernadette's boss or colleague at Zangen.
Mark Berry as the Pit Boss in The Monetary Insufficiency that Sheldon meets in a Las Vegas casino.
Evan Charest as the Croupier in The Monetary Insufficiency that Sheldon meets in a Las Vegas casino.
Casper Smart as Travis in The Gorilla Dissolution who works for the stage crew of Penny's gorilla movie.
Efrain Gomez as the Zangen Employee in The Collaboration Contamination who gets the visiting Bernadette a coffee and ignores Penny.