A guide structure of a vehicle seatbelt includes a belt guide. The belt guide is provided at one of a left corner and a right corner defined by a left side frame, a right side frame, and an upper frame. The one corner faces a belt pulled out from a seatbelt device. The left side frame and the right side frame extend vertically. The upper frame connects an upper end of the left side frame to an upper end of the right side frame. The belt guide protrudes upwardly with respect to the upper frame and forwardly with respect to the left side frame and the right side frame so that when the belt is placed on an occupant who sits on the seat, a portion of the belt that is placed on a shoulder of the occupant is guided by the belt guide.