A rotor 120 for a spinning reel 100 for fishing, includes a cylindrical portion 121, a first rotor arm 210, a second rotor arm 220 and a reinforcement portion 127. The cylindrical portion 121 has a rear end opening 126 that is open. The first rotor arm 210 extends forward from an outer peripheral portion of the cylindrical portion 121 and configured to couple to a first bail support portion 21 including a line roller 3. The second rotor arm 220 is at a position opposing the first rotor arm 210, extending forward from the outer peripheral portion of the cylindrical portion 121, and configured to couple to a second bail support portion 22 holding an end of a bail 23 that extends from the first bail support portion 21. The reinforcement portion 127 has a wall portion that is thicker than a surrounding portion, and is disposed on an inner peripheral portion of the cylindrical portion 121 in a position at which the first rotor arm 210 is disposed.
