Andreas du Plessis de Richelieu (24 February 1852 – 25 March 1932) was a Danish naval officer and businessman who became a Siamese admiral and minister of the navy. He was granted the Thai noble title Phraya Chonlayutthayothin (Thai: พระยาชลยุทธโยธินทร์). He commanded forces at the Phra Chulachomklao Fortress in the Paknam Incident of 13 July 1893, that ended the Franco-Siamese War, and went on to become the first and only foreign-born commander-in-chief of the Royal Thai Navy, from 16 January 1900 to 29 January 1901.