The Glenariff Iron Ore and Harbour Company (GIOH) was a railway and harbour company in Glenariff, County Antrim, in what is now Northern Ireland. It operated Red Bay Pier on the Antrim coast and about 4 miles (6.4 km) of narrow gauge railway between the pier and Cloughcor Mines in Glenariff. The railway was 3 ft (914 mm) narrow gauge and carried iron ore from the mines to the pier, where it was loaded onto cargo ships for export to ironworks in Scotland and England.