A mounting structure for wheel rotation sensor 40 includes a brake flange 20, a bracket 30, and a wheel rotation sensor 40. The brake flange 20 is disposed near a sensor rotor 10 fixed to an axle of a wheel, includes a flange surface 21 intersecting the axle, and is fixed to a vehicle body side. Moreover, boss portions 26 protrude integrally from the flange surface 21 of the brake flange 20. The bracket 30 is fixed to the brake flange 20 while contacting distal portions 27 of the boss portions 26. The wheel rotation sensor 40 is fixed to the bracket 30, faces a rotation trajectory of the sensor rotor 10, and detects the sensor rotor 10 in a direction substantially parallel to the axle.