Lionel Sackville-West, 2nd Baron Sackville, GCMG (19 July 1827 – 3 September 1908), was a British diplomat.

Then, he was appointed Envoy Extraordinary and Minister Plenipotentiary to the United States, a post he held until 1888, when he was declared persona non grata for writing of the Murchison letter.

Lord Sackville had seven children by a Spanish dancer, Josefa de la Oliva (née Durán y Ortega, known as Pepita).

Soon after his death one of these, calling himself Ernest Henri Jean Baptiste Sackville-West, claimed to be a lawful son and his father's heir.

The case came before the English courts of law in 1909–1910, and it was decided that the children of this union were all illegitimate, as Pepita's husband, Juan Antonio Gabriel de Oliva, was alive during the whole period of his wife's connection with Sackville-West.