A buckle holding structure for holding a buckle unit on a seat cushion, the buckle unit having: a belt of which one end is fixed to a vehicle body; and a buckle fixed to the other end of the belt, the buckle holding structure including: a band that has elasticity, has a predetermined width, and is folded in a U shape to form a folded portion, wherein both ends of the band are fixed to a rear end of the seat cushion so as to be disposed on the same plane in a width direction of the band; the belt of the buckle unit is inserted into a gap formed between both ends of the band, which is fixed to the rear end of the seat cushion, and the folded portion; and the buckle is caught by the folded portion.