A roof apparatus includes a weather strip including a portion to be retained, and first and second seal portions which are connected to an upper end of the portion to be retained. A thickness of the first seal portion gradually reduces from a first end portion positioned at an upper end side of the portion to be retained towards a first turned back portion, and gradually increases from the first turned back portion towards a second end portion provided at a lower end portion of the portion to be retained. A thickness of the second end portion is smaller than that of the first end portion. A distance in a vehicle height direction from a lower end of the first seal portion to the first turned back portion is greater than a distance from an upper end of the first seal portion to the first turned back portion.