The story follows Rahul Mithaiwala, a 40-year-old businessman from Mumbai, who boards the Chennai Express to fulfill his grandfather's dying wish: immersing his ashes in Rameshwaram. His life takes a sharp turn when he helps Meenamma, the daughter of a powerful local don, board the train.

: Rahul (Shah Rukh Khan), a 40-year-old bachelor, embarks on a journey to Rameshwaram to immerse his grandfather's ashes. On the train, he helps a woman named Meenamma (Deepika Padukone) board, only to find himself entangled with her powerful South Indian family.