A turnable headrest includes a headrest body and a headrest rod. The headrest body is wrapped around and hinged to a horizontal rod of the headrest rod, and two vertical rods of the headrest rod are inserted into a seat. The turnable headrest further includes a fixed tooth, a torsion spring, a rotary tooth, and a reset tension spring. A headrest body locking portion, a headrest body rotary tooth portion, and a turned headrest body locking portion are disposed on the fixed tooth. A rotary tooth portion is disposed on the rotary tooth. When the rotary tooth portion is mated with the headrest body locking portion on the fixed tooth, the headrest body is locked at an initial use position. When the rotary tooth portion is mated with the headrest body rotary tooth portion on the fixed tooth, the headrest body is at a turnable position. When the rotary tooth portion is mated with the turned headrest body locking portion on the fixed tooth, the headrest body is locked at a flat position. The turnable headrest has advantages such as a strong self-locking ability, a small quantity of parts, a simple structure, and low costs.