Weatherstrip

A weatherstrip includes an attachment portion, a flexible seal wall, a flexible bridging wall, and a hollow portion. The seal wall extends from an upper portion of the attachment portion toward the front of a vehicle, is turned up, and extends toward the rear of the vehicle. A lower surface of a peripheral portion of a roof panel toward the rear of the vehicle and a lower surface of a peripheral portion of a rear door panel toward the front of the vehicle contact the seal wall from above. The bridging wall bridges the seal wall and the attachment portion. The hollow portion is surrounded by the attachment portion, the seal wall, and the bridging wall.