A cylinder for a combustor includes a cylindrical member, a first cooling passage defined in the cylindrical member and a second cooling passage defined in the cylindrical member, and a supply port extender. The first cooling passage includes a supply port that opens to an outer peripheral surface of the cylindrical member. The second cooling passage includes a discharge port that opens to the outer peripheral surface of the cylindrical member downstream of the supply port. The supply port extender includes a first wall that is disposed between the supply port and the discharge port and extends away from the outer peripheral surface of the cylindrical member and a second wall that is disposed upstream of the supply port and extends away from the outer peripheral surface of the cylindrical member.