Moy Castle is a ruined three-storey tower house sitting on rocks at the head of Lochbuie, on the Isle of Mull. It was built in the early 15th century by Hector MacLean. He was the younger brother of Maclean of Duart and founder of the renamed MacLaines of Lochbuie.

The castle saw action during bitter clashes with the Campbells, who captured it in 1674, although it was later returned. It was abandoned as a residence in 1752 when Lochbuie House was built.