Lieutenant Colonel Dr. Anthony St. Clare Rex de Costa, MBE, CAVF (15 June 1920 - 9 April 1971) was a renowned Sri Lankan medical doctor and soldier. He was the commanding officer of the Ruhunu Regiment, a doctor in the Ceylon Defence Force during World War II and a vice president of the World Veterans Federation. He was assassinated by the JVP during the 1971 Insurrection.