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The Best Episodes of The Big Bang Theory Season 9

Every episode of The Big Bang Theory Season 9 ranked from best to worst. Discover the Best Episodes of The Big Bang Theory Season 9!

Binge this in 7h 42m•Peaking at 9.0/10

Physicists Leonard and Sheldon find their nerd-centric social circle with pals Howard and Raj expanding when aspiring actress Penny moves in next door.

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Episode Rankings

  1. #1 Fan Favorite
    The Big Bang Theory Season 9 Episode 1 - The Matrimonial Momentum
    6.8/10(4293 votes)

    #1 - The Matrimonial Momentum

    S9:E1

    After driving to Vegas to get married, Penny struggles with Leonard’s confession that he kissed another girl. Also, Sheldon doesn't know how to act after Amy pushes pause on their relationship.

    Director:Mark Cendrowski
    Writer:Unknown

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  2. The Big Bang Theory Season 9 Episode 2 - The Separation Oscillation
    7.3/10(3686 votes)

    #2 - The Separation Oscillation

    S9:E2

    Leonard confronts the woman he kissed on the North Sea in an attempt to set Penny's mind at ease. Also, Sheldon films a special episode of "Fun with Flags" after his breakup with Amy, and Bernadette feels guilty about withholding a secret from Penny.

    Director:Mark Cendrowski
    Writer:Unknown

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  3. The Big Bang Theory Season 9 Episode 3 - The Bachelor Party Corrosion
    7.7/10(3759 votes)

    #3 - The Bachelor Party Corrosion

    S9:E3

    The guys' science skills are put to the test when they get a flat tire during Leonard's bachelor party weekend in Mexico. Also, the girls force Penny to finally tell her family that she eloped with Leonard.

    Director:Mark Cendrowski
    Writer:Unknown

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  4. The Big Bang Theory Season 9 Episode 4 - The 2003 Approximation
    7.4/10(3547 votes)

    #4 - The 2003 Approximation

    S9:E4

    Sheldon learns of an impending change in his living arrangements and decides to revert back to 2003, a simpler time before he met Leonard and Penny. Also, Howard and Raj form a band to play at the Comic Book Store.

    Director:Mark Cendrowski
    Writer:Unknown

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  5. The Big Bang Theory Season 9 Episode 5 - The Perspiration Implementation
    7.4/10(3470 votes)

    #5 - The Perspiration Implementation

    S9:E5

    The guys take a fencing lesson from Barry Kripke and Sheldon finds himself in an awkward position when Kripke expresses interest in Amy. Also, when Stuart struggles to get female customers at the Comic Book Store, Penny, Amy and Bernadette come by to help him out.

    Director:Mark Cendrowski
    Writer:Unknown

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  6. The Big Bang Theory Season 9 Episode 6 - The Helium Insufficiency
    7.2/10(3538 votes)

    #6 - The Helium Insufficiency

    S9:E6

    In the midst of a nation-wide helium shortage, Sheldon and Leonard take desperate measures to get the supplies they need. Also, Penny and Bernadette download a dating app on Amy's phone to try and find her a new man.

    Director:Mark Cendrowski
    Writer:Unknown

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  7. The Big Bang Theory Season 9 Episode 7 - The Spock Resonance
    7.9/10(3655 votes)

    #7 - The Spock Resonance

    S9:E7

    Wil Wheaton interviews Sheldon for a Star Trek documentary where he reveals the ring and his plan to propose to Amy. Bernadette wants to start renovating the house and the topic of starting a family together with Howard is brought up.

    Director:Nikki Lorre
    Writer:Unknown

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  8. The Big Bang Theory Season 9 Episode 8 - The Mystery Date Observation
    7.9/10(3667 votes)

    #8 - The Mystery Date Observation

    S9:E8

    Sheldon, Wolowitz and Koothrappali post an online advertisement to find Sheldon a new girlfriend. Also, when Amy is coy with details about a guy she is dating, Penny and Bernadette decide to spy on her.

    Director:Mark Cendrowski
    Writer:Unknown

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  9. The Big Bang Theory Season 9 Episode 9 - The Platonic Permutation
    7.7/10(3662 votes)

    #9 - The Platonic Permutation

    S9:E9

    Sheldon and Amy try hanging out as friends when they spend Thanksgiving together at the aquarium. Also, Wolowitz reluctantly agrees to volunteer at the soup kitchen with Bernadette, Raj and Emily, and Penny discovers that Leonard knows more about her than she thought.

    Director:Mark Cendrowski
    Writer:Unknown

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  10. The Big Bang Theory Season 9 Episode 10 - The Earworm Reverberation
    8.3/10(4122 votes)

    #10 - The Earworm Reverberation

    S9:E10

    Sheldon has a revelation when he realizes why a song was stuck in his head. Also, Amy invites Dave over for dinner despite their previously awkward date, and Wolowitz and Koothrappali become obsessed with a fan of their band, "Footprints on the Moon".

    Director:Mark Cendrowski
    Writer:Unknown

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  11. The Big Bang Theory Season 9 Episode 11 - The Opening Night Excitation
    9.0/10(5980 votes)

    #11 - The Opening Night Excitation

    S9:E11

    After more than five years of dating, Sheldon and Amy spend their first night together. Also, Leonard, Wolowitz, and Koothrappali must decide who will take their extra Star Wars movie ticket.

    Director:Mark Cendrowski
    Writer:Unknown

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  12. The Big Bang Theory Season 9 Episode 12 - The Sales Call Sublimation
    7.4/10(3304 votes)

    #12 - The Sales Call Sublimation

    S9:E12

    Penny gets more than she bargained for when Leonard agrees to meet with a psychiatrist on her behalf. Also, Sheldon and Koothrappali collaborate on an astronomical discovery, and Wolowitz and Bernadette can't believe what they are feeling after Stuart moves out.

    Director:Mark Cendrowski
    Writer:Unknown

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  13. The Big Bang Theory Season 9 Episode 13 - The Empathy Optimization
    7.4/10(3320 votes)

    #13 - The Empathy Optimization

    S9:E13

    After having to deal with a sick Sheldon, Leonard, Penny and the gang try to treat themselves to a Sheldon-free weekend.

    Director:Mark Cendrowski
    Writer:Unknown

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  14. The Big Bang Theory Season 9 Episode 14 - The Meemaw Materialization
    7.5/10(3375 votes)

    #14 - The Meemaw Materialization

    S9:E14

    Meemaw meets Amy, but it isn't all roses. Meemaw seems to have an axe to grind with her. Sheldon comes to Amy's defense, but not before Meemaw lets a little secret of his slip.

    Director:Mark Cendrowski
    Writer:Unknown

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  15. The Big Bang Theory Season 9 Episode 15 - The Valentino Submergence
    7.5/10(3322 votes)

    #15 - The Valentino Submergence

    S9:E15

    Sheldon and Amy host a live Valentine's Day episode of Fun with Flags, Leonard and Penny grapple with getting older, Howard and Bernadette find a surprise in their hot tub and Raj is torn between Emily and the cute girl he met at the Comic Bookstore.

    Director:Mark Cendrowski
    Writer:Unknown

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  16. The Big Bang Theory Season 9 Episode 16 - The Positive Negative Reaction
    7.4/10(3451 votes)

    #16 - The Positive Negative Reaction

    S9:E16

    When the gang finds out about Bernadette’s pregnancy, they celebrate by singing karaoke. Also, Bernadette is concerned when Wolowitz freaks out over her pregnancy announcement, and Wolowitz is convinced he must make more money to provide for the baby.

    Director:Mark Cendrowski
    Writer:Unknown

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  17. The Big Bang Theory Season 9 Episode 17 - The Celebration Experimentation
    7.6/10(3478 votes)

    #17 - The Celebration Experimentation

    S9:E17

    After more than nine years together, the gang finally celebrates Sheldon’s birthday, surprising him with a special guest.

    Director:Mark Cendrowski
    Writer:Unknown

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  18. The Big Bang Theory Season 9 Episode 18 - The Application Deterioration
    7.5/10(3250 votes)

    #18 - The Application Deterioration

    S9:E18

    Leonard, Sheldon, and Wolowitz run into problems when they file for a patent for their infinite persistence gyroscope. Also, Penny, Amy and Bernadette give Koothrappali dating advice when Emily reaches out to him after their breakup.

    Director:Mark Cendrowski
    Writer:Unknown

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  19. The Big Bang Theory Season 9 Episode 19 - The Solder Excursion Diversion
    7.4/10(3178 votes)

    #19 - The Solder Excursion Diversion

    S9:E19

    Amy is shocked at a revelation from Sheldon after she buys him a new laptop. Also, Koothrappali sells out Leonard and Wolowitz after they lie to their wives in order to attend an early screening of a movie.

    Director:Mark Cendrowski
    Writer:Unknown

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  20. The Big Bang Theory Season 9 Episode 20 - The Big Bear Precipitation
    7.4/10(3150 votes)

    #20 - The Big Bear Precipitation

    S9:E20

    Sheldon spills a secret of Leonard’s when the two take a weekend cabin trip with Penny and Amy. Also, when Koothrappali goes overboard with pregnancy gifts, Wolowitz and Bernadette must draw the line.

    Director:Mark Cendrowski
    Writer:Unknown

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  21. The Big Bang Theory Season 9 Episode 21 - The Viewing Party Combustion
    7.4/10(3148 votes)

    #21 - The Viewing Party Combustion

    S9:E21

    Everyone must choose sides when a small argument between Leonard and Sheldon erupts into a heated fight during a group get-together.

    Director:Mark Cendrowski
    Writer:Unknown

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  22. The Big Bang Theory Season 9 Episode 22 - The Fermentation Bifurcation
    7.4/10(3088 votes)

    #22 - The Fermentation Bifurcation

    S9:E22

    The gang goes to a wine bar and runs into Penny’s old boyfriend, Zack. Also, Bernadette gets stuck spending the evening with Sheldon when she can’t go wine tasting with the group, and things don’t go as planned when Koothrappali introduces his new girlfriend, Claire.

    Director:Nikki Lorre
    Writer:Unknown

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  23. The Big Bang Theory Season 9 Episode 23 - The Line Substitution Solution
    7.4/10(3101 votes)

    #23 - The Line Substitution Solution

    S9:E23

    Sheldon hires Stuart to spend the day with Amy when he’d rather go to a movie screening. Also, Leonard’s mother, Beverly, comes to town and Penny struggles to make a connection with her.

    Director:Anthony Rich
    Writer:Unknown

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  24. The Big Bang Theory Season 9 Episode 24 - The Convergence Convergence
    7.8/10(3497 votes)

    #24 - The Convergence Convergence

    S9:E24

    Chaos ensues when Leonard’s recently divorced parents, Alfred and Beverly, and Sheldon’s devoutly religious mother, Mary, come to town. Also, Wolowitz and Koothrappali think the government is out to get them when they are contacted about their guidance system.

    Director:Mark Cendrowski
    Writer:Unknown

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Season 9 Ratings Summary

"The Matrimonial Momentum" is the best rated episode of "The Big Bang Theory" season 9. It scored 6.8/10 based on 4293 votes. Directed by Mark Cendrowski and written by Unknown, it aired on 9/21/2015. This episode is rated 0.5 points higher than the second-best, "The Separation Oscillation".