Charles Phelps "Charlie" Smyth (/smaɪθ/; February 10, 1895 – March 18, 1990) was an American chemist. He was educated at Princeton University and Harvard University. From 1920 to 1963 he was a faculty member in the Princeton Department of Chemistry, and from 1963 to 1970 he was a consultant to the Office of Naval Research.