A seatbelt device comprises a webbing, a bag body and an anchor member. The webbing is applied to the body of a vehicle occupant sitting on a seat. The bag body is provided along a length direction of the webbing, and the bag body is disposed at one side of the webbing and can be inflated by pressure of a fluid supplied from a length direction one side of the bag body. A deployment portion through which the fluid can pass is provided in the bag body, being disposed at width direction outer sides and a thickness direction another side of the webbing. An insertion hole is formed in the anchor member, through which the webbing and the bag body are inserted. The webbing is folded at the thickness direction one side when applied to the body of the sitting vehicle occupant, and the deployment portion of the bag body is disposed in the insertion hole.