A valve timing controller includes: a driving-side rotating body rotating in synchronization with a crankshaft of an internal combustion engine; a driven-side rotating body disposed coaxially with a rotation axis of the driving-side rotating body and rotating integrally with a valve opening and closing camshaft; advancing and retarding chambers formed between the driving-side and driven-side rotating bodies; a control valve unit controlling supply and discharge of a fluid to and from the advancing and retarding chambers; and a check valve unit disposed upstream of the control valve unit in a supply flow passage. A pressure space is provided between the control valve and check valve units, the control valve unit has a flow passage structure, and the check valve unit includes a supply flow passage and a return check valve.