To prevent application of the push-back force of a subject for coupling to an operating part facing the outer periphery by limiting the range of movement of the subject for coupling such as a D-ring.

The animal coupler includes: a body 5 with a bifurcated part 4 close to a distal end 3 side extended from a base part 2 to which a base ring 1 is rotatably coupled; a C-shaped coupling ring 6 stored in the body 5 in such a way as swingable in both ways; and a spring 8 for energizing the coupling ring 6 in such a way as to hold the ring at a coupling position. A coupling end 6a of the coupling ring 6 advances to an opening part 4a of the bifurcated part 4 from one side 4b of the bifurcated part to be coupled to the subject 7 for coupling to close the opening part 4a, and retreats from the bifurcated part 4 to open the opening part 4a to release the coupling with the subject 7 for coupling. The coupling ring 6 has the operating part 6b facing a side of the body 5 to be operated to retreat to a coupling releasing position against the energization of the spring 8.