A tampon applicator 100 according to the present invention includes an outer tube 110 and an inner tube 120. The outer tube 110 includes an outer-tube tip end portion 111 having a locking portion 213 and an outer-tube rear end portion 112 having a protrusion 200. The protrusion 200 is capable of passing by the locking portion 213 from the outer-tube rear end portion 112 side to the outer-tube tip end portion 111 side. When the protrusion 200 is positioned on the outer-tube tip end portion 111 side of the locking portion 213, the locking portion 213 locks the protrusion 200 to prevent the inner tube 120 from returning to the outer-tube rear end portion 112 side of the locking portion 200.