An automobile headrest includes a mounting component, a pillow portion detachably connected with the mounting component, a movable block provided with engaging protrusions arranged vertically, a side of the pillow portion adjacent to the mounting component is provided with a groove, at least part of the movable block is movably arranged in the groove, an end of the movable block disposed with the engaging protrusions is exposed from a groove opening of the groove, the pillow portion is provided with a vertically oriented slideway adjacent to the groove opening, the mounting component is provided with a sliding block matched with the slideway, the sliding block is provided with an engagement portion matched with the engaging protrusions, the sliding block is arranged in the slideway, the engaging protrusions are protruded from the groove opening and partially arranged in the engagement portion, when the pillow portion is connected with the mounting component.