An instrument manipulator and a robotic surgical system including an instrument manipulator are provided. In one embodiment, an instrument manipulator includes a plurality of independent actuator drive modules, each of the plurality of actuator drive modules including an actuator output, wherein each of the actuator outputs are configured to independently actuate a corresponding actuator input of a surgical instrument without force input from another actuator output. The instrument manipulator further includes a frame housing the plurality of independent actuator drive modules, the frame including a distal end from which each of the actuator outputs distally protrude for engaging the corresponding actuator inputs of the surgical instrument.