A shift fork position detecting device for a manual transmission is provided. The manual transmission includes a coupling sleeve constituting a synchronizer, a shift fork movable with the coupling sleeve and an actuator for moving the shift fork. The actuator has a stationary main body and a reciprocal output member operatively connected to the shift fork. The shift fork position detecting device includes a magnet mounted on the output member of the actuator, and a magnetic sensor mounted on the main body of the actuator to cooperate with the magnet for detecting the position of the shift fork.