Blackhead Antrim Lighthouse marks the northern extremity of Belfast Lough. This octagonal tower was designed by William Douglass, Engineer to the Commissioners of Irish Lights. It was completed in 1902 and was painted red. An explosive fog signal was established at the same time as the light.
On the 20th August 1929 the colour of the tower was changed to white.
From September 1965, the explosive fog signal was accompanied by a brilliant flash of light when sounding during the hours of darkness.
On 23rd September 1965 Blackhead Antrim Lighthouse was converted to electric and the intensity of the light was increased giving a range of 27 nautical miles. At the same time the duration of the flash was decreased to 0.15 seconds, the character being Fl W 3 secs (fl 0.15, ec 2.85). The lantern equipment is a 920mm catadioptric annular lens with a PRB22 gearless drive and MBI 400W lamps in a UVLA lampchanger.
The fog-signal was discontinued in February 1972.
On the 31st July 1975 the Lightkeepers were withdrawn from the Station and since then it has been in the care of a part-time Attendant.
On the 1st April 1992 the Radiobeacon Calibration service at Mew Island was discontinued and moved to Blackhead Antrim. In more recent times utilisation of radio direction finders by Mariners has been to a great extent superceded by more modern technology. For this reason the Commissioners discontinued their Medium Frequency Radiobeacon service on 1st February 1999.