An occupant protection device for a vehicle includes a seat, a three-point seatbelt device, and a belt airbag device. An occupant to board the vehicle is to sit on the seat. The three-point seatbelt device includes a seatbelt extendable across a front of an upper body of the occupant sitting on the seat. The belt airbag device includes a belt airbag that is provided at a shoulder belt section, which is extendable from a shoulder to a waist of the occupant, of the seatbelt, and that is configured to be deployed when a collision occurs. The belt airbag includes a belt-direction deployment section extendable and deployable along the shoulder belt section, and an intersecting-direction deployment section extendable and deployable in a direction intersecting the shoulder belt section. The sections are configured to form a single bag by being coupled to each other below a head of the occupant sitting on the seat.