A torque detecting device detects a torsional torque between a first shaft and a second shaft based on a torsional displacement of a resilient member linking the first shaft and the second shaft coaxially. The torque detecting device is provided with: a magnet fixed to the first shaft; a first yoke fixed to the second shaft and arranged to be rotatable with respect to the magnet; a second yoke fixed to the second shaft and arranged to be rotatable together with the first yoke with respect to the magnet; a magnetic flux collector which collects magnetic flux; and a magnetic sensor which detects magnetic flux density. The magnetic flux collector is located to face both the first yoke and the second yoke. The magnetic sensor is located between the first yoke, from among the first yoke and the second yoke, and the magnetic flux collector, and detects the magnetic flux density between the first yoke and the magnetic flux collector.