A touchless actuation system for a toilet includes a touchless sensor, a motor assembly, and a processing circuit. The touchless sensor is located within a closed reservoir of the toilet. The processing circuit is configured to receive a signal from the touchless sensor and to detect an object within a detection region based on the signal. The detection region is external to the closed reservoir. The processing circuit is configured to facilitate flushing of the toilet through interaction with the motor assembly when the object is detected.