Clifford Ambrose Truesdell III (February 18, 1919 – January 14, 2000) was an American mathematician, natural philosopher, and historian of science.

After high school, he spent two years in Europe learning French, German, and Italian, and improving his Latin and Greek.

In particular, a course in partial differential equations "taught me the difference between an ordinary good teacher and a great mathematician, and after that I never cared what grade I got in anything.

Truesdell taught at Indiana University 1950–61, where his students included James Serrin, Jerald Ericksen, and Walter Noll.

Following Truesdell's criticisms of awkward style in scientific writing,[11] the journal accepted papers in English, French, German, and Latin.