The Roommate is a 2011 thriller film directed by Christian E. Christiansen and starring Minka Kelly, Leighton Meester, Danneel Harris, Cam Gigandet, and Alyson Michalka. It was theatrically released on February 4, 2011.

The film begins with Sara (Minka Kelly) going to college and finding her room. While she is there she sees that the bed is empty. Also, she meets two other girls, Tracy (Alyson Michalka) and Tracy's roommate, and she is invited to join the two at a frat party. While she is there she meets a guy in the band named Stephen (Cam Gigandet) and they flirt with each other. During the party, Sara sees Tracy drunk and dancing about to take off her top for frat guys with a camera. Sara consoles her and takes her back to her room. While going back to her room she meets her new roommate, Rebecca (Leighton Meester). The two slowly becomes friends and Sara introduces Rebecca to her other friends.

However, her reactions to them seem cold and distant. She is especially cold to Sara's best friend, Irene Crew (Danneel Harris). Sara seems to be oblivious to any of this and becomes close to Rebecca and seemingly more distant with Tracy, especially when she takes Sara out one night and ditches her. These two reconcile and their relations appear to go back to normal. Sara's closeness to Rebecca becomes strained when she becomes very clingy and obsessive about their friendship. One example of this is when Rebecca sits outside of Tracy's door and glares at her. Tracy attempts to warn Sara about Rebecca, but she does not seem to believe her. Rebecca ultimately reveals her true nature by attacking Tracy in the shower by ripping out her belly ring, threatening to kill her if she tells anybody and that she is a bad influence on Sara.

A fearful Tracy decides to move to another hall. During this time Sara and Steven start to become even closer and Rebecca becomes more jealous and obsessive about their friendship. Also, Sara is having trouble with her ex-boyfriend Jason (Matt Lanter) back at home. During a date Stephen and Sara decide to have sex. Sara's ex-boyfriend calls her. However, she is not present and Rebecca impersonates her over the phone. He invites her over (not knowing he is drunk and cannot see very well also not knowing he invited Rebecca over), Jason lies in bed while Rebecca sits on top of him. She takes a pocket knife from the back of her bra and slices his throat. Rebecca's attempts at keeping Sara in her life begin to become more desperate and the true measure of her insanity is revealed. During Thanksgiving, when Sara wants to leave with Steven instead of going with Rebecca to her parents Rebecca violently beats herself and cuts herself with box cutter. Rebecca lies to Sara and tells her that she was attacked in an alley looking for their lost kitten. Later, Rebecca ties up Sara's friend Irene. Sara and Steven fight with Rebecca to save Irene. Rebecca holds a knife against Sara. Sara than takes the knife from her and stabs her in the back saying "We were never friends." killing her.