SS Infanta Isabel de Borbon was a steam ocean liner and mail ship launched in 1912 in Scotland and operated by the Compañía Transatlántica Española (CTE).

William Denny and Brothers built Infanta Isabel de Borbon at Dumbarton in Scotland, launching her on 29 September 1912 and completing her on 15 March 1913.

[1] At the same time Swan, Hunter and Wigham Richardson built her sister ship Reina Victoria-Eugenia, and there were significant technical differences between the two.

[2] Denny's based Infanta Isabel de Borbon's propulsion on that of the refrigerated cargo liner Otaki which they had launched in 1908.

CTE ordered a similar combination of two triple-expansion engines and one low-pressure turbine for Infanta Isabel de Borbon.

Infanta Isabel de Borbon could go astern, slowly forward or manoeuvre using only her piston engines.

On 12 March 1913 Reina Victoria-Eugenia started her maiden voyage from Barcelona via Malaga, Cádiz, Tenerife and Montevideo to Buenos Aires.

[6] In the First World War both Infanta Isabel de Borbon and Reina Victoria-Eugenia seem to have made some trips New York.

[7] On 26 August 1914 Infanta Isabel de Borbon left Barcelona for New York with all of her available berths taken by US citizens[8] returning home because of the outbreak of war.

[7] For a time their route was revised to include additional calls at Almería and Rio de Janeiro.