Abstract: This essay explores the origin and evolution of “Theoretical Mechanics” as the first mechanics course in universities. The analysis on textbooks in English, French, Russian, German and Chinese reveals that “theoretical mechanics” originated from Newton's term “rational mechanics”, which French scholars used as the name of the course. Then the French usage was introduced to Russia and China to form “theoretical mechanics”. Meanwhile, “Theoretical Mechanics” was used as the name of textbooks in the United Kingdom and the United States.