Brian Thomas Smith (born May 13, 1977) is an American actor and comedian known for playing the dim-witted Zack Johnson in The Big Bang Theory, and his appearances on Fear Factor and The Amazing Race Season 7. He has also made guest appearances on Two and a Half Men and The 100 Greatest TV Quotes & Catchphrases.

Family and Personal life

Brian Thomas Smith has a younger brother, Greg, who participated with him on The Amazing Race. Smith graduated from Central Missouri State University (he was also a Sigep) before moving to Los Angeles. He was a member of the sketch comedy troupe, The Exploding Pajamas.


Smith has appeared in commercials for Miller Lite, Pizza Hut, Burger King, State Farm, Lopez Tonight, Chevrolet, Heineken, Carl's Jr., Coors Light, Budweiser, Taco Bell, DirecTV, Pop Chips, Buffalo Wild Wings, Honda, Applebee's, and Audi spots as well as being featured in a new Progressive Insurance commercial.

Smith appeared on the reality television competition series The Amazing Race 7. Smith and his younger brother, Greg made it to Leg 7 of the race. The two were involved in a car accident during the sixth leg that injured their cameraman and pushed them to last place, but they caught up to the team in front of them resulting in a footrace. They placed sixth overall.



Year Title Role Notes
2004 Duel Short
2006 The 12th Man Adam Rump TV movie
2007 What Ever Happened to Gavin Buckmaster? Gavin Short
2008 No Place Like Home Matt Short
2009 The Moonlighters Bob Short
Tourist Attraction Dereck
Perry's Fairies Short
The Indies Sean Short
2010 All American Zombie Drugs Bobby
2012 Lucy in the Sky with Diamond Brian Short
Surprise Matthew Short
Hot Neighbours Judd Short
Concrete Blondes Karl Short
2013 Casual Guy
2015 Lethal Seduction Randy TV movie


Year Title Role Notes
2006 Two and a Half Men Emmett 1 episode
2010 A Good Knight's Quest Agent One 8 episodes
The Indies Sean 2 episodes:
"Pictures Up! Part 1" (season 1: episode 1)
"Le film de France" (season 1: episode 4)
2010–present The Big Bang Theory Zack Johnson Recurring role, 7 episodes:
"The Lunar Excitation" (season 3: episode 23)
"The Alien Parasite Hypothesis" (season 4: episode 10)
"The Justice League Recombination" (season 4: episode 11)
"The Toast Derivation" (season 4: episode 17)
"The Thanksgiving Decoupling" (season 7: episode 9)
"The Cooper Extraction" (season 7: episode 11)
"The Fermentation Bifurcation" (season 9: episode 22)
2010–11 Casual: The Series Guy Season 1-3 (series regular; 17 episodes)
2012 Happy Endings Nick 1 episode
Wolfpack of Reseda Vance Season 1 (series regular; 5 episodes)
Suit Up Bjorn Hansen Recurring role, 4 episodes:
"No Money, No QB" (season 1: episode 3)
"The Pistol Formation" (season 1: episode 4)
"The Beer Knight Rises" (season 1: episode 5)
"Death or Glory" (season 1: episode 8)