A rotary force controlling apparatus and an image forming apparatus including the same are provided. The rotary force controlling apparatus includes a clutch device having a shaft, and a rotary body mounted at one end of the shaft. A housing receives and rotates together with the shaft. A power transferring member is rotatably mounted in the housing and selectively rotates the housing by a clutch inserted between the housing and the power transferring member. A positioning unit protrudes from the periphery of the housing and positions a stop location of the rotary body. A solenoid unit is spaced apart from the clutch device and is selectively turned on and off. The positioning unit includes a first positioning unit that positions an initial location of the rotary body when the solenoid unit is turned on; and a plurality of second positioning units that are separated from the first positioning unit and stop the rotary body at a predetermined location when the solenoid unit is turned off. Since the solenoid unit is turned off when the rotary body is stopped, the solenoid unit is prevented from being overheated.