Tommy Thong Bee Koh (born 1937) is a Singaporean diplomat, lawyer, and academic who has had a distinguished career in international law and diplomacy. He served as Singapore's Permanent Representative to the United Nations (1968–1974 and 1974–1984) and as Ambassador to the United States (1984–1990). He is widely known for his role as President of the Third United Nations Conference on the Law of the Sea and as Ambassador-at-Large for Singapore's Ministry of Foreign Affairs.