A weatherstrip includes: a trim portion and a seal portion. The trim portion includes: a main body portion including a first and second side wall portions provided on a vehicle outer side and a vehicle inner side, respectively; a first and second holding lips extending from the first and second side wall portions, respectively; and a first extended wall portion extending from a distal end portion of the first side wall portion. In a trim portion attaching direction, a distal end portion of the first side wall portion is positioned at, or on the weatherstrip inner circumferential side of, a boundary portion between the trim portion and an inner circumferential surface of the seal portion, and a distal end portion of the second side wall portion is positioned on the weatherstrip inner circumferential side of a distal end portion of the first extended wall portion.