Francis August Schaeffer' (30 January 1912 – 15 May 1984) was an American Evangelical Christian theologian, philosopher, and Presbyterian pastor. He is most famous for his writings and his establishment of the L'Abri community in Switzerland. Opposed to theological modernism, Schaeffer promoted a more historic Protestant faith and a presuppositional approach to Christian apologetics which he believed would answer the questions of the age.
Schaeffer's wife, Edith (Seville) Schaeffer, became a prolific author in her own right. Schaeffer was also the father of—initially a collaborator with, and after his death the object of criticism from—Frank Schaeffer, an author, film-maker and painter.