PS Tredagh was a paddle steamer passenger vessel operated by the Drogheda Steam Packet Company from 1876 to 1902 and the Lancashire and Yorkshire Railway from 1902 to 1912.
She was built by A. & J. Inglis of Glasgow for the Drogheda Steam Packet Company and transferred to the Lancashire and Yorkshire Railway in 1902 when they took over the business of the Drogheda company.
The name Tredagh is a corruption of the name Drogheda.
In 1904 she was sold and scrapped in Preston.
- ^ Railway and Other Steamers, Duckworth. 1962