HEADREST

A headrest (1) is provided with: left and right, mutually spaced headrest pillars (2, 2); a fixed-side member (4) disposed on the headrest pillars (2, 2) ; a movable-side member (5) linked to the fixed-side member (4) via a movable mechanism and enabled to be movable in a front-rear direction with respect to the fixed-side member (4); and a front-rear lock mechanism that locks or unlocks the movement of the movable-side member (5) in the front-rear direction with respect to the fixed-side member (4). The front-rear lock mechanism is provided with a plurality of engaged portions (10, 10) disposed on the outer side than the left and right headrest pillars (2, 2) in a width direction, and a lock member (11) including a plurality of engaging portions (71, 71) that lock the movement of the movable-side member (5) by respectively engaging the plurality of engaged portions (10, 10).