René de La Croix, count de Castries (French pronunciation: [ʁəne də la kʁwa də kastʁ]; 6 August 1908 – 17 July 1986) was a French historian and a member of the House of Castries.

[1] He was the sixteenth member elected to occupy seat 2 of the Académie française in 1972.

[1] He wrote under the pen name Duc de Castries, a courtesy title drawn from his family’s extinct dukedom.

[1] He grew up in a castle in Gaujac, Gard, and attended school in Nîmes and Versailles.

[1] In 1985, he gave the Château de Castries to the Académie française.