Peter John Kreeft is an American professor of philosophy who has taught at Boston College and The King's College. A convert to Catholicism, he has established himself as a prominent voice in Christian apologetics and philosophy. Kreeft is a prolific author, having written over eighty books focused on Christian philosophy, theology, and apologetics. He is known for his work formulating Twenty Arguments for the Existence of God, which he developed together with Ronald K. Tacelli and published in their Handbook of Christian Apologetics.