The disclosure herein discloses a rebar tying tool that ties plural rebars using a wire. The rebar tying tool includes a housing and a twisting motor, and may include a twisting mechanism that twists the wire around the plural rebars by the twisting motor. The twisting mechanism may include a screw shaft, a gripping member that grips the wire in cooperation with rotation of the screw shaft, a first reduction mechanism that reduces and transmits rotation of the twisting motor to a relay shaft, and a second reduction mechanism that reduces and transmits rotation of the relay shaft to the screw shaft. The first reduction mechanism may be a coaxial reduction mechanism, and the second reduction mechanism may be a parallel-axis reduction mechanism.