Saundersfoot Lighthouse was built in 1848 to mark the entrance to Saundersfoot Harbour. In 1861 it was illuminated using candles, but unsurprisingly these were ineffective.
Saundersfoot became a port for exporting anthracite mined from local pits. Coal wagons were transported along a specially built railway track to the harbour.
An ingenious tidal float in the harbour indicated when entry into the harbour was impossible. At low water, a red glass masked the light. This was operated via wires which connected the float to the glass. This system was discontinued in 1947 when local mines were closed around the outbreak of the Second World War, and traffic declined. However, it was reinstated in 1954 when the port began to thrive as a yachting harbour.
A navigation light is now mounted on the roof of the building and replaced an unusual lantern design with iron glazing bars. The old lighthouse lantern was divided into eight panes and bolted to the top of the dome. This lantern survived until around 1930. In 1971 the harbour master still had possession of it. Its current whereabouts is unknown.