The lighthouse at Blackhead marks the northern extremity of Belfast Lough, it is situated on a cliff top giving its lantern a height of 45 meters above high water spring tides giving it a range of 27 nautical miles. The present light dates from 1902, the octagonal tower and associated buildings were designed by William Douglas, originally it was painted red in August 1929 the colour was changed to white.

The light was converted to electric in September 1965 when its intensity was increased giving its present range of 27 nautical miles, the lamp lens is 920 mm in diameter and is lit by a 400 watt bulb, the fog signal ceased to be used in 1972.

The 31st of July 1975 saw the last permanent keepers leaving the station when it was automated, now the light although automatic has a part time keeper living on the station. Previously there was radio beacon equipment at blackhead with the advent of satellite navigation radio beacons became obsolete and were discontinued in 1999.

The image on the right is St Johns Lighthouse in County Down.