Great Island (Oileán Mór an Barraigh in Irish) is the name of an island in Cork Harbour, just outside Cork city, at the mouth of the River Lee. The town of Cóbh is situated on the island, which is connected by bridge to Fota Island to the north, which in turn is connected by a causeway to the mainland. A railway line runs out through both islands to Cóbh.
The island's name comes from the Irish, meaning "Great island of the Barrys", referring to a powerful Norman family who settled in the area. The original name of the island was Oilean Ard na Neimheadh, the "High (or important) island of Neimheadh". Neimheadh was a leader who invaded Ireland in ancient times.
Due to the close proximity of Great island to the amenities on Fota Island, the development of a dedicated car-free walking and biking trail around the perimeter of Great island will be a major tourist attraction, particularly as the walking trail can be connected by ferry to the dedicated rail trail already existing between Passage West and Cork city.