Flat Top Island Light is an inactive lighthouse located on Flat Top Island, a small island off the entrance to Mackay harbor at the mouth of Pioneer River, about 6.5 kilometres (4.0 mi) east of Mackay, Queensland, Australia. It used to mark the river entrance for shipping and the direction of the port, as well as highlighting close by shoals at Shoalwater Point and a reef off Hay Point. At 6 metres (20 ft) from the ground to the lantern floor, it is the shortest of Queensland's timber-framed iron clad lighthouses.