The purpose of the present invention is to provide a headrest configured so that the formation of scratches on the headrest and the occurrence of abnormal noise, which are caused by the contact of the headrest with the upper end of a headrest guide, are prevented. A headrest (10) is mounted to the upper end of a seat back (1) through a headrest pillar (2) and a headrest guide (3), which is mounted to the seat back (1) in such a manner that the upper end of the headrest guide (3) is exposed at the upper end of the seat back (1) and which supports the headrest pillar (2) so that the height of the headrest pillar (2) can be adjusted. The headrest (10) has a recess (30a) formed in the bottom (10a) thereof so as to face the upper end (3a) of the headrest guide (3). The surface which forms the recess (30a) is set so as to be separated from the upper end (3a) of the headrest guide (3).