The child, who local media have identified as a five-year-old boy named Rayan, was reportedly playing near the well in the town of Tamrout, 100km (62 miles) from Chefchaouen.
Rayan is believed to have fallen about 32m (104ft) through a narrow opening.
Rescue operations, led by Morocco's Civil Protection Directorate, have been ongoing since Tuesday evening.
Despite suffering a significant fall, footage from a camera lowered into the well showed that the boy remains alive and conscious, though he appeared to be suffering from some minor head injuries.