TSS Slieve Donard was a steam turbine passenger and cargo vessel operated by the London and North Western Railway from 1921 to 1923, and the London, Midland and Scottish Railway from 1923 to 1948.

[1] She was built by Cammell Laird in 1921 as the last ship for the London and North Western Railway and put on the Holyhead - Dublin route.

She was named after the Slieve Donard (Irish: Sliabh Dónairt,[2] derived from Sliabh Domhanghairt/Domhanghart)[3] mountain in County Down, Northern Ireland.

It is the highest peak of the Mourne Mountains.

She was generally employed on the Thursday mid-day trip from Dublin for the cattle-dealers returning from market.