Castle Tioram is a ruined castle that sits on the tidal island Eilean Tioram in Loch Moidart, Lochaber, Highland, Scotland. It is located west of Acharacle, approximately 80 km (50 mi) from Fort William. Though hidden from the sea, the castle controls access to Loch Shiel. It is also known to the locals as "Dorlin Castle". The castle is a scheduled monument.

A tidal island is a raised area of land within a waterbody, which is connected to the larger mainland by a natural isthmus or man-made causeway that is exposed at low tide and submerged at high tide, causing the land to switch between being a promontory/peninsula and an island depending on tidal conditions.