Minalini 'Milli' Chakravarty (Sonam Kapoor) is a physiotherapist who works for the IPL. Her mother Manju (Kirron Kher) hopes that she will find a man someday, stating that it will be even better if the bloke belongs to royalty. As fate would have it, her services are called for by a royal family whose King's legs are failing him. Dr. Milli travels to the Sambhalgarh palace and meets the rigid Queen, Nirmala Devi Rathore (Ratna Pathak), who is not amused by Milli's enthusiasm and clumsiness. Milli finds that her casual way of living does not appeal to the royal family whose strict disciplinary rules demand otherwise. She meets Yuvraj Vikram Singh Rathore (Fawad Afzal Khan), the prince, whose distant personality makes him similar to his parents. Milli also discovers that Divya, the youngest child of the family, has an interest in acting and is planning to run away from home. Milli befriends Divya but keeps trying to convince her to not run away. The King keeps avoiding his exercises and this troubles Milli because she is determined to cure him so she turns to Vikram for help. He gives Milli the same answer that the Queen gave her, "If she cannot handle the job, she may leave." Milli gets furious and accuses the Royal Family to be stubborn, rigid and self-centered. Vikram reconsiders but the King refuses.
Just when Milli is deciding to leave, she learns the reason for the King's unwillingness to be cured from the Royal Servant Ram Sevak: ten years ago, Ambar, the family's eldest son, died in a car crash. The King had gifted a sports convertible to him and the two went for a ride. Ambar lost control of the car due to over-speeding and passed away, and the King's legs became disabled and he went into a coma for six months. Since then, the Queen changed. The Palace used to be fun and everyone would throw parties and laugh but after the accident, everybody changed. Milli shames the King into getting over his guilt and forces him to perform his exercises. The King befriends Milli and he finally agrees.
Milli gets kidnapped, and when Vikram saves her, she kisses him in her drunken state, though regrets it the next morning. The two start falling for each other. Milli confesses her love for him but Vikram refuses to acknowledge it, saying that they come from two different stocks. He is also engaged to a lady of his status Kiara (Aditi Rao Hydari). Divya runs away to try out for auditions in Jaipur. Milli informs the Queen that she knew about Divya's plans. The Queen becomes furious and Milli is ordered to leave. Divya returns and tells Nirmala that she came back because of Milli. The King surprises Nirmala by standing up, and admits that he saw Divya run away. He tells her that this is what Milli has been trying to teach them; to love life as it is. Milli however is heartbroken due to Vikram's refusal.
Vikram breaks off his engagement with Kiara and confesses his love for Milli and the royal couple gives him their blessings, telling him to go find her in Delhi. Vikram finds Milli, wins her mother's approval by proposing to Milli in her style, and hence, as the wife of Vikram Singh Rathore, Milli is given the title of the Royal Misfit.
