TV series
Smart is the new sexy.
Physicists Leonard and Sheldon find their nerd-centric social circle with pals Howard and Raj expanding when aspiring actress Penny moves in next door.
Streaming, rental and purchase options
Checked Sep 2, 2026
The Big Bang Theory is available to stream on DirecTV On Demand, HBO (Via Hulu), HBO Max, HBO Max (Via Amazon Prime), and YouTube TV in United States. You can also rent or buy it from Google Play, Amazon, Apple TV, and Fandango at Home. Use the direct links below to open the provider.
Physicists Leonard and Sheldon find their nerd-centric social circle with pals Howard and Raj expanding when aspiring actress Penny moves in next door.
Choose an episode, then use the watch options above for the show.
Episode 1
Brilliant physicist roommates Leonard and Sheldon meet their new neighbor Penny, who begins showing them that as much as they know about science, they know little about actual living.
Directed by James BurrowsWritten by Chuck Lorre, Bill PradyGuest stars Brian Patrick Wade, Vernee Watson
Episode 2
Leonard volunteers to sign for a package in an attempt to make a good impression on Penny, but when he enlists Sheldon for help, his attempt at chivalry goes terribly awry.
Directed by Mark CendrowskiWritten by Chuck Lorre, Bill Prady, David Goetsch, Robert Cohen
Episode 3
Leonard asks a woman out after he finds out that Penny is seeing someone.
Directed by Mark CendrowskiWritten by Chuck Lorre, Steven Molaro, Bill PradyGuest stars Sara Gilbert, Sherry Weston, Allen Nabors, Treisa Gary
Episode 4
Sheldon's getting fired forces him to explore what life has to offer outside physics, leaving Leonard to take drastic action to snap his friend out of his funk.
Directed by Bob Koherr, Mark CendrowskiWritten by Chuck Lorre, Bill Prady, David Litt, Lee AronsohnGuest stars Laurie Metcalf, Mark Harelik, Sierra Edwards, Netta Most
Episode 5
Fearing he's wasting his time on Penny, Leonard ends up making a connection with Leslie.
Directed by Andrew D. WeymanWritten by David Goetsch, Steven Molaro, Jennifer GlickmanGuest stars Sara Gilbert
Episode 6
Penny hosts a Halloween party, putting Leonard, Sheldon, Wolowitz, and Koothrappali through a new test of their social skills.
Directed by Mark CendrowskiWritten by David Goetsch, David Litt, Robert CohenGuest stars Kimberly Kevon Williams, Brian Patrick Wade, Erin Allin O'Reilly, Rachel Cannon, Cynthia Holloway
Episode 7
With Wolowitz AWOL with one of her friends, Penny's recruited to fill in for him on the guys' Halo team
Directed by Mark CendrowskiWritten by Chuck Lorre, Bill Prady, Jennifer Glickman, Lee AronsohnGuest stars Brooke D'Orsay, James Hong, Carol Ann Susi, Kimberly Brooks
Episode 8
Raj's parents set him up on a blind date, but just when he discovers he can talk to her, she shows interest in Sheldon.
Directed by Ted WassWritten by Steven Molaro, David Goetsch, Lee Aronsohn, Robert CohenGuest stars Alice Amter, Brian George, Sarayu Blue
Episode 9
When they're invited to present at a physics conference, Sheldon's reluctance to share the credit leads to a tiff between him and Leonard, and Penny's intervention only exacerbates the situation.
Directed by Joel MurrayWritten by Bill Prady, Chuck Lorre, David Goetsch, Lee Aronsohn, Stephen EngelGuest stars Talbott Lin, Howard Chan
Episode 10
Leonard and Sheldon each lie to avoid seeing Penny's concert, but Sheldon's is a bit too complicated for his own good.
Directed by Mark CendrowskiWritten by Chuck Lorre, Bill Prady, Lee AronsohnGuest stars DJ Qualls
Episode 11
With his friends knowing how sour he acts when sick—and avoiding him as a result—Sheldon is nursed by Penny, who hasn't a clue what she's in for.
Directed by Mark CendrowskiWritten by Chuck Lorre, Bill Prady, Lee Aronsohn, Stephen EngelGuest stars Erin Allin O'Reilly, Carol Ann Susi
Episode 12
With Sheldon rattled over meeting Dennis, a 15-year-old physicist who's smarter than he, Leonard helps him look for a way to debunk Dennis's research.
Directed by Mark CendrowskiWritten by David Goetsch, Steven Molaro, Jennifer Glickman, Stephen EngelGuest stars Emma Degerstedt, Joel Brooks, Mark Harelik, Austin Lee
Episode 13
Sheldon finds himself booted from the gang's Physics Bowl team and replaced with Leslie, so he forms his own team, hoping to prove he's superior.
Directed by Mark CendrowskiWritten by Jennifer Glickman, Bill Prady, Stephen Engel, Robert CohenGuest stars Sara Gilbert, Mark Harelik, Sandra Marquez, Sergio Enrique, Adam Gregor
Episode 14
When delivery of another collectible leads to Penny's lashing out at Leonard, he decides it's time to give up his habit, much to his friends' protestation.
Directed by Mark CendrowskiWritten by Bill Prady, Steven Molaro, Stephen EngelGuest stars Andrew W. Walker
Episode 15
The rest of the gang fall for Sheldon's twin sister, and Leonard's plan to win her heart is derailed when Sheldon declares he'll be the one to decide who can date her.
Directed by Mark CendrowskiWritten by Chuck Lorre, Bill Prady, Lee AronsohnGuest stars Courtney Henggeler
Episode 16
Penny wants to throw a surprise party for Leonard, but Sheldon's indulgence at an electronics store throws her off-track.
Directed by Mark CendrowskiWritten by Bill Prady, David Goetsch, Steven Molaro, Lee AronsohnGuest stars Vernee Watson, Judith Moreland, Ronald Hunter, Chuck Carter
Episode 17
Penny's break-up spurs Leonard to summon the courage to ask her out, and each goes to Sheldon for advice on their upcoming date.
Directed by Mark CendrowskiWritten by Chuck Lorre, Bill Prady, Steven Molaro, Lee AronsohnGuest stars James Hong
Episode information updated Sep 14, 2026
Johnny GaleckiLeonard Hofstadter
Jim ParsonsSheldon Cooper
Kaley CuocoPenny
Simon HelbergHoward Wolowitz
Kunal NayyarRajesh Koothrappali
Melissa RauchBernadette Rostenkowski
Mayim BialikAmy Farrah Fowler
Kevin SussmanStuart Bloom
CBSUnited States
Chuck Lorre ProductionsUnited States
Warner Bros. TelevisionUnited States
