To provide a seat cover capable of being very easily attached/detached to/from a seat and protecting the seat and a backrest appropriately at all times.

The seat cover 3 is formed to have a box shape including: an upper surface part 6 for covering a part between the front edge of the seat 1 and the upper edge of the backrest 2; a front end part 7; a rear end part 8; and left and right side surface parts 9a, 9b. The rear end part 8 and the rear surface of the backrest 2 are pivotally attached so as to be rotatable by a pivotal attachment part 5. When a vehicle is travelled, the opening state of the seat 1 is held by performing rotation so as to allow the seat cover 3 to be opened to the rear part of the backrest 2 with the pivotal attachment part 5 as a center. When the vehicle is not travelled, the cover 3 is rotated from the rear part of the backrest 2 to the upper part of the seat 1, so that the seat 1 and the backrest 2 are internally enclosed.