Thomas A. Mensah (12 May 1932 – 7 April 2020) was a Ghanaian judge, law professor and diplomat who served as judge and president of the International Tribunal for the Law of the Sea (ITLOS) from 1996 to 1999 and continued as a judge from 1999 to 2005. He was the first president of the tribunal. Before his appointment to the tribunal, Mensah was Ghana's High Commissioner to South Africa and a former Assistant Secretary-General at the International Maritime Organization (IMO).