Thomas West, 3rd Baron De La Warr (July 9, 1577 - June 7, 1618) was the Englishman for whom the state, river, and American Indian tribe called "Delaware" (in the United States) were named.

He was son to Thomas West, 2nd Baron De La Warr and Anne Knollys, daughter of Sir Francis Knollys and Catherine Carey.

West received his education at Queen's College, Oxford. He served in the army under Robert Devereux, 2nd Earl of Essex, and in 1601 was charged with supporting Essex's ill-fated insurrection against Queen Elizabeth, but he was acquitted of those charges and succeeded his father as Baron De La Warr in 1602 and became a member of the Privy Council.

Lord De La Warr headed the contingent of 150 men who landed in Jamestown on 10 June 1610, just in time to persuade the original settlers not to give up and go home to England. He had been given instructions by The London Virginia Company to kidnap Native American children. These instructions also sanctioned the murder of the Iniocasoockes , the cultural leaders of the local Powhatans. Lord De La Warr proceeded to initiate the First Anglo-Powhatan War , which has been described as an act of genocide. He had been appointed governor-for-life (and captain-general) of Virginia, and he outfitted their three ships and recruited and equipped those men at his own expense. Leaving his deputy Sir Samuel Argall (circa 1580 - circa 1626) in charge, Lord De La Warr returned to England and published a book about Virginia, The Relation of the Right Honourable the Lord De-La-Warre, of the Colonie, Planted in Virginia, in 1611. He remained the nominal governor, and he had received complaints from the Virginia settlers about Argall's tyranny in governing them for him, so Lord De La Warr set sail for Virginia again in 1618, to investigate those charges. He died en route and was buried at sea.