Salvador Bermúdez de Castro y O'Lawlor, 2nd Duke of Ripalda, Marquis of Lema (1 November 1863, in Madrid – 20 January 1945) was a Spanish noble, politician and lawyer who served as Minister of State during the reign of Alfonso XIII.

He was born in Madrid, the son of Manuel Bermúdez de Castro y Díez (1811–1870) a senator and Minister for the Interior and Foreign Affairs, and María de la Encarnación O’Lawlor y Caballero (1830–1908), youngest daughter of Joseph O'Lawlor (1768–1850), an Irish-born Spanish general and governor of Granada.

His cousin Richard Lalor was an Irish nationalist member of the British House of Commons.

A deputy for Oviedo (1891–1923), he served as Minister for Foreign Affairs 1919–21, 1917, 1913–15; Mayor of Madrid 1903–4 and Governor of the Bank of Spain (1922–3).

[4] Late in life, he was one of the 22 jurists who signed the "opinion on the illegitimacy under the operating powers of the 18th of 1936 July" [es], a report drafted in 1938 and commissioned by the Francoist faction during the Civil War that served as ad-hoc legitimation for the 1936 coup d'etat.