A damper device includes first and second rotary members, elastic members, and seat members. The first rotary member includes an annular chamber, and first engaging portions provided in the annular chamber. The second rotary member includes a second engaging portion. The elastic members are aligned in a circumferential direction in the annular chamber, and elastically couple the first and second rotary members in a rotational direction. Each seat member is disposed between a circumferential end surface of each elastic member and both the first engaging portions and the second engaging portion. Each seat member includes first and second contact surfaces. The first contact surface contacts the circumferential end surface of each elastic member. The second contact surface contacts the second engaging portion. The first and second contact surfaces tilt at angles to prevent a radially outward force from acting on each seat member when each elastic member is elastically deformed.