León María Ignacio Agapito Guerrero y Francisco, GCrM KGCR (March 24, 1915 – June 24, 1982), better known simply as Leon Ma. Guerrero III, was a Filipino diplomat and novelist, and was one of the foremost Filipino nationalists of his era. A partner in the law practice of senator Claro M. Recto, he became Undersecretary of Foreign Affairs during the Magsaysay administration. His then controversial advocacy of Asia for the Asians and espousal of a realistic re-examination of relations with the United States are now commonly accepted as being ahead of their time.