RMMV Athlone Castle was a British passenger liner built by Harland & Wolff for the Union-Castle Line's mail service from Southampton to Cape Town, South Africa route.

[2][3] The 25,564 GRT motor ship Athlone Castle was built at the Harland & Wolff shipyard in Belfast, Northern Ireland.

The ship was powered by two 10 cylinder Burmeister & Wain diesel engines developing 24,000 bhp and a speed of 19.5 knots.

On 22 May 1936 the Athlone Castle left Southampton for her maiden voyage to Cape Town, where she arrived on 7 June.

In May 1947, the Athlone Castle returned to the Union-Castle Line's postal service and for the following years sailed from England to South Africa as before the war.