Shy, introverted, and kind-hearted Surinder "Suri" Sahni (Shahrukh Khan) is an office worker for Punjab Power. He quietly falls in love with the daughter of his former professor, beautiful and vivacious Tania "Taani" Gupta (Anushka Sharma), whom he first sees during the preparations for her wedding. Upon their first meeting however, Taani jokingly berates and blames him for setting an impossible set of standards (reiterated by her father) that she was never able to meet as a child. A short while later, Taani's father suffers a heart attack when the entire wedding party learns that her fiance and his family were killed in a traffic accident. Fearing that Taani will be alone in the world, the professor asks Suri to marry her. Suri concedes; Taani tearfully agrees only to please her father.

After a hasty wedding, Suri takes Taani to his ancestral home in Amritsar. While his good nature leads Suri to treat her with exceptional care and patience, he is too frightened to profess his love for her. However, Taani tells him that while she will try to be a good wife, she can never love him due to having no love left within her. Suri still continues to indulge her every desire. This includes frequent visits to the cinema to see song and dance films which appeal to Taani's fantasies about romance and her passion for dancing. She soon asks for Suri's permission, which he grants, to take an expensive dance class with the company Dancing Jodi to escape her mundane life at home.

During one visit to the cinema, Suri feels inadequate in comparison to the strong, masculine images that Taani admires and later asks his childhood friend Balwinder "Bobby" Khosla (Vinay Pathak), a hair-saloon owner, for advice on how to win her love. Bobby is eager to help and suggests a complete makeover (removing his moustache, changing his hairstyle, and giving him a new set of clothing including a pair of sunglasses). Suri is thus transformed into the swaggering, loud, rude, and fun-loving "Raj", named by Suri after the hero in the movie that Taani had admired. He joins the dance class and by chance or, as he believes, by divine intervention becomes Taani's partner in the competition. Despite Raj's initial crudeness a result of Surinder's inexperience with women and his attempt to emulate the "cool" images from movies he and Taani become friends as they work together on their dance routine. Suri feels encouraged when Taani does not tie a rakhi (holy thread) on "Raj's" wrist during the festival of Raksha Bandhan (for to do so would indicate that she thought of him only as a brother). Thus, after a period of time, Raj declares his love for her.

Suri's ruse poses a dilemma for both of them. Taani enters into a period of internal conflict, desperately wanting to escape from her despair-filled life through finding a new person to love. Yet despite wanting to escape her loveless marriage, Taani feels compelled to stay with Suri due to the promise that she made to her father. Suri also faces an extraordinary paradox: Taani's sheer misery as his wife in contrast to her delight with his fabricated alter ego "Raj." He thus attempts to win Taani's love as Suri, an act which only alienates her further. She eventually runs away to find Raj in order to tell him the predicament she is in, hoping he will help her. He offers to elope with her, which she agrees to tearfully. They set the date for their elopement to the next night, the night of the competition.

On the day of the competition, Suri takes Taani to the Golden Temple in order to garner God's blessings for her competition that night--and internally, also for her life with Raj. While there Taani has an epiphany in which she believes God has shown her a sign that tells that her marriage to Suri is divinely inspired. For the first time she reflects on her husband and becomes aware of the strength and integrity of Suri's character. Taani thus tells Raj that she cannot run away with him. She leaves him in what appears to be a state of shock with tears in his eyes. When the time comes for their performance Taani is stunned to see Suri, rather than Raj, join her on stage. It is at that moment that Taani grows to love Suri (rather than Raj) as she discovers his passionate love for her