Ynys Gaint is a small island in the Menai Strait connected to the town of Menai Bridge on Anglesey by a causeway.
Ynys Gaint lies close to the Anglesey shore at OS reference SH561725, between Ynys Faelog and Ynys Castell. Between 1942 and 1944 the island held a Royal Air Force air/sea rescue unit, with several high speed launches, and part of the island is currently occupied by an Army camp.