A vehicle cabin structure includes a vehicle cabin and a handrail having an inverted U-shape and including an upper portion extending in a width direction of a vehicle along a ceiling surface of the vehicle cabin, and right and left vertical portions connected to both ends of the upper portion and extending downward along right and left side surfaces of the vehicle cabin from the respective ends of the upper portion, in which the right and left vertical portions of the handrail are fixed to the right and left side surfaces of the vehicle cabin, respectively.