The LEYSIAN was a British steamer. Travelling from Belfast to Cardiff, she sunk on 24 February 1917. Her wreck lies outside Abercastle, Pembrokeshire. There were no casualties.

There are conflicting accounts associated with the wrecking, the most common being that she mistook Strumble Head for St. David’s Head in fog, but other accounts refer to her being chased onto the rocks by a German U-boat, the compass having been tampered with, and a mutiny on board by around 50-muleteers.