Southwold Lighthouse was built to replace the lighthouses at Orfordness to the south, which were under threat of erosion.
The lighthouse was first lit on 3rd September 1890. In 1923 a vapour burner was installed, replacing the oil lamp. This continued until 1938 when the lighthouse was automated and electrified.
The optic was re-used from Happisburgh Low Light, which had been demolished in 1884.
With the decommissioning of Orfordness Lighthouse, the top beehive section of the fixed optic was removed, and a new revolving LED optic installed above the old lens, changing its character. To compensate for the loss of Orfordness light, the range of the light increased from 17 to 24 miles. The new light was exhibited in December 2012.
A section of the top beehive of the optic is on display at the base of the tower, and another section was returned to Happisburgh Lighthouse where it is also on display.