Donaghadee Lighthouse is located at the end of the harbour breakwater.
The small port was once the Irish terminal for the short route to Scotland via Portpatrick, a distance of around 22 miles. The crossing had been operating since 1662. But with the increase in larger vessels, access into Portpatrick became more difficult, and in strong easterly winds, access into Donaghadee was hazardous.
In the 1820s, a new harbour was built, designed by John Rennie.
In November 1834, the Donaghadee Harbour Commissioners indicated their willingness to build a light on the south pier. Trinity House rejected this, and in 1835 the Ballast Board was authorised to take control.
The lighthouse was established in 1836 and displayed a fixed white light towards Belfast Lough and the harbour. It was built of Anglesey limestone and was originally unpainted. The grey lighthouse was later painted white.
A cottage for the lightkeeper was acquired by the Ballast Board in 1864 in the town.
Until the Belfast and Down Railway reached Donaghadee in 1861, there were serious road transportation issues. However, the Larne and Stranraer ferry was now developing and took over as the main route in 1871.
On 12th May 1900, a fire seriously damaged the lighthouse lantern and optic. A temporary light was set up during the repair and replacement of the lantern and optic.
Donaghadee Lighthouse was the first to be converted to electric operation on the Irish coast. It was electrified on 2nd October 1934, and the Chaine Tower in Larne was electrified the following year. Following the electrification of Donagahadee Lighthouse, the light became unwatched.
Many of the buoys in the estuary were serviced at the lighthouse, but this operation later moved to the buoy depot at Ferris Point near Larne.
In 1953 a siren fog signal was erected on the gallery and was controlled from the Harbour Board office.
The harbour of Donaghadee was featured in a recent TV police drama, Hope Street, in 2021.
The former cottages for Mew Island Lighthouse can be found along the road at Warren Road.