There is provided a seat gap hiding structure in a vehicle seat where a cutout portion is formed on a seat cushion to arrange a seat belt therein, and a strip-shaped member is provided on a seat cover to correspond to the cutout portion at a part of the cutout portion, which is other than an arrangement position of the seat belt to cover a gap around the seat belt. One end portion of the strip-shaped member is fixed to the seat cover and the other end portion thereof is movably fixed to the seat cover using an elastic member. When the strip-shaped member is moved from an original position where the strip-shaped member covers the gap of the cutout portion, the elastic member generates an elastic force to return the strip-shaped member to the original position.