A seat may includes a seat base, a seat cover that is capable of being detachably attached to the seat base, a first engagement member that is attached to a circumferential surface of the seat base, a second engagement member that is attached to the seat cover, and a third engagement member that is attached to the circumferential surface of the seat base. The first engagement member is capable of engaging the second engagement member when the seat cover is attached to the seat base, so as to fix the seat cover to the seat. The first engagement member is capable of engaging the third engagement member when the first engagement member does not engage the second engagement member.