Frederick Charles Copleston (10 April 1907 – 3 February 1994) was an English Roman Catholic Jesuit priest, philosopher, and historian of philosophy, best known for his influential multi-volume A History of Philosophy (1946–75).

Copleston achieved a degree of popularity in the media for debating the existence of God with Bertrand Russell in a celebrated 1948 BBC broadcast; the following year he debated logical positivism and the meaningfulness of religious language with his friend the analytic philosopher A. J. Ayer.

In addition to his influential multi-volume History of Philosophy (1946–75), one of Copleston's most significant contributions to modern philosophy was his work on the theories of Saint Thomas Aquinas. He attempted to clarify Aquinas's Five Ways (in the Summa Theologica) by making a distinction between in fieri causes and in esse causes. By doing so, Copleston makes clear that Aquinas wanted to put forth the concept of an omnipresent God rather than a being that could have disappeared after setting the chain of cause and effect into motion.

Frederick Copleston