The Swansea Harbour Trustees were given the power to provide a lighthouse at the outer Mumbles in the Harbour Act of 1791; in July 1792 the Trustees contracted for the erection of the lighthouse and work began, but the half-finished structure collapsed in October 1792. In 1793 the plans of the local architect William Jernegan were accepted and the lighthouse was finally completed and lit in 1794.
Mumbles Lighthouse originally displayed two open coal fire lights—one above the other—to distinguish it from the two lighted towers of St. Ann's Head Lighthouse and Flatholm Lighthouse’s single light. The coal lights in braziers were expensive and difficult to maintain so were quickly replaced with a single oil powered light consisting of Argand lamps with reflectors within a cast iron lantern. The original two lights are still reflected in the two tier structure of the tower. The fort or battery which surrounds the southern side of the lighthouse was built in 1860 by the War Department.
Trinity House assumed responsibility for Mumbles Lighthouse from the British Transport Docks Board on 1 November 1975. In 1995 the lighthouse was converted to solar powered operation.
The lighthouse is now monitored and controlled from Trinity House’s Planning Centre in Harwich, Essex.