The present disclosure provides a chair with a rotatable armrest, comprising a seat body, which is provided with an armrest, a backrest and a rotating member; wherein the backrest is arranged at a position on one end portion of the seat body, the rotating member is fixed on one end of the seat body near the backrest, the armrest is rotatablely connected with the seat body through the rotating member, and the armrest is capable of rotating roughly horizontally with respect to the seat body. According to the present disclosure, a user can leave the chair from one side of the seat body, moreover, when the user is leaving the chair, the rotated armrest can still provide help for the user.