Southwold Lighthouse is a coastal mark for passing shipping and guides vessels into Southwold Harbour. The lighthouse is situated near the centre of the seaside resort of Southwold, midway between Lowestoft and Orford, the round white tower stands amongst rows of small houses.

Construction of Southwold Lighthouse began in 1887 under the supervision of Sir James Douglass, Engineer in Chief to Trinity House. The lighthouse replaced three local lighthouses which were under threat from severe coastal erosion at Orfordness to the South. While the masonry tower was built a temporary light was shown from a wooden structure which was first lit on 19th February 1889.

The present lighthouse came into operation on 3rd September 1890. The light was originally provided by an Argand burner, this was replaced by a Matthews incandescent oil burner in 1906. A Hood 100mm petroleum vapour burner was installed in 1923 and remained until the station was electrified and demanned in 1938. Two red sectors mark shoals to the north and the Sizewell Bank to the south, the main navigation light is white.

A local Attendant visits the lighthouse regularly to conduct routine maintenance. It has become an icon of the town associated with the local brewery, Adnams. The structure is Listed Grade II.