Aughinish is a small island located in north county Clare, in Ireland (53.09°N 9.04°W) on the south shore of Galway Bay.

The island was originally connected to county Clare, but in 1755 that connection was lost due to the tsunami effect of the massive Portuguese earthquake. Then the British built the existing causeway to county Galway to service their troops in the Martello tower on the island. So to this day, access to Aughinish, county Clare is still only through county Galway.

The island is approximately two miles wide and a mile from the northernmost tip to the southernmost point and has approximately fifty inhabitants.