To provide a flap for a tire capable of reducing damage by rubbing to a tube of a peripheral end part of a wing part of the flap.

A flap 1 for a tire is a flap for a tire installed in a tube of a tube type tire, and includes a cylindrical base part 1a installed between the tube and a rim, and a pair of wing parts 1b continuously connected to both sides of the base part 1a. The peripheral end part of the wing part 1b of the flap is formed in a shape of continuously changing in a wave shape between the most distant position and the nearest position in a distance from the axis of the base part 1a. Therefore, even when the flap 1 is dislocated in the peripheral direction to the tube, a position of rubbing the peripheral end part of the wing part 1b with the tube is always changed.