Eeragh Lighthouse is an active lighthouse located on Rock Island, one of the Brannock Islands, part of the Aran Islands archipelago in County Galway, Ireland. It marks the north-western entrance to Galway Bay and the port of Galway known as the North Sound. Due to its location it is also known as the Aran North Lighthouse. The lighthouse on Inisheer at the south-eastern end of the islands was also constructed at the same time. Eeragh and Inisheer both became operational in 1857.