Georges Thierry d'Argenlieu (French pronunciation: [ʒɔʁʒ tjɛʁi daʁʒɑ̃ljø]), in religion Father Louis of the Trinity, OCD (7 August 1889 – 7 September 1964), was a Discalced Carmelite friar and priest, who was also a diplomat and French Navy officer and admiral; he became a major personality of the Forces navales françaises libres.

D'Argenlieu served on the Du Chayla as a midshipman, taking part in the campaign in Morocco, which led to the Treaty of Fez, in 1912.

During the campaign, he was awarded the Legion of Honour, and befriended Hubert Lyautey, something that d'Argenlieu later recalled as one of the happy memories in his life.

During the First World War, d'Argenlieu served in the Mediterranean; in 1915, while on leave in Malta, he became a member of the Secular Order of Discalced Carmelites.

In 1941, he rose to counter admiral; he undertook several missions to administer French colonies loyal to Free France.

In 1943, he was made commanding officer for the naval forces in Great Britain On 14 June 1944, he ferried de Gaulle to France aboard the destroyer La Combattante, and entered Paris with him on 25 August.

In 1958, sick, d'Argenlieu resigned his position of chancellor of the Ordre de la Libération and withdrew to monastery life again.