RMS Durham Castle was a passenger ship built for the Union-Castle Mail Steamship Company in 1904.

[3] She sank on 26 January 1940 after hitting a mine probably laid by the German submarine U-57.

She was part of a convoy sailing up the English Channel in June 1918, in company with the Union-Castle RMS Kenilworth Castle and escorted by the cruiser HMS Kent and five destroyers.

On 4 June HMS Kent was leaving the convoy, but owing to a misunderstanding, cut across Kenilworth Castle's bows.

She was taken in tow, bound for Scapa Flow as a base accommodation ship, but on 26 January 1940 she struck a mine off Cromarty and sank.