Willard attended William Jewell College, and later graduated from Tennessee Temple College in 1956 with a B.A. in Psychology, and from Baylor University in 1957 with a B.A. in Philosophy and Religion. He went to graduate school at Baylor University and the University of Wisconsin—Madison, earning a Ph.D. in Philosophy with a minor in the History of Science in 1964.

Willard taught at the University of Wisconsin in Madison from 1960—1965. Since then he has taught at the University of Southern California in Los Angeles, where he served as Director of the School of Philosophy from 1982—1985. He has also held visiting appointments at UCLA (1969) and the University of Colorado (1984).

His publications in philosophy are concerned primarily with epistemology, the philosophy of mind and of logic, and with the philosophy of Edmund Husserl. He has translated many of Husserl's early writings from German into English.

In addition to teaching and writing about philosophy, Willard gives lectures and writes books about Christianity and Christian living. His book The Divine Conspiracy was Christianity Today’s Book of the Year for 1999 1999 Book Awards | Christianity Today | A Magazine of Evangelical Conviction. Another of his books, Renovation of the Heart, won Christianity Today’s 2003 Book Award for books on Spirituality and The Association of Logos Bookstores' 2003 Book Award for books on Christian Living. Christianity Today Book Awards 2003 | Christianity Today | A Magazine of Evangelical Conviction

Willard believes passivity to be a widespread problem in the Church (loosely summed up in his phrase "Grace is not opposed to effort {which is action}, but to earning {which is attitude}"). He emphasizes the importance of deliberately choosing to be a disciple of Jesus Christ (someone being with Jesus, learning to be like Him). An important outgrowth of the choice to be identified as a disciple of Jesus is the desire to learn about activities that aid spiritual transformation into the likeness of Christ.

In this regard, being an apprentice of Jesus (someone being with Jesus, learning to be like Him), involves learning about activities that might help one grow in the fruit of the spirit, namely love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, and self-control (Galatians 5:22-23). Such activities might include spiritual exercises practiced throughout the ages such as prayer, fellowship, service, study, simplicity, chastity, solitude, fasting. Willard explains the crucial role of engaging in spiritual exercises in his book The Spirit of the Disciplines: Understanding How God Changes Lives-- a book that was written after In Search of Guidance: Developing a Conversational Relationship with God.

Willard has a recommended reading page on his website listing specific titles by Thomas a Kempis, William Law, Frank Laubach, William Wilberforce, Richard Baxter, Charles Finney, Jan Johnson, Dietrich Bonhoeffer, Jeremy Taylor, Richard Foster, E. Stanley Jones, William Penn, Brother Lawrence, Francis de Sales, and others.

He has been influenced by many, including Jacques Maritain, Aquinas, Augustine, P.T. Forsyth, John Calvin and John Wesley, William Law, Andrew Murray, Richard Baxter, Teresa of Avila, Francis de Sales, Brother Lawrence, and the Rule of St. Benedict.

He has served on the boards of the C.S. Lewis Foundation and of Biola University.

Translations of Works by Husserl

• Philosophy of Logic and Mathematics (1993). Dordrecht/Boston: Kluwer Academic Publishers, ISBN 0-7923-2262-2
• Philosophy of Arithmetic, (2003). Dordrecht: Kluwer Academic Publishers, ISBN 1-4020-1546-1 (Hardbound), ISBN 1-4020-1603-4 (paperback)

Christian books

• The Spirit of the Disciplines: Understanding How God Changes Lives (1988). San Francisco: Harper and Row, ISBN 0-06-069442-4
• The Divine Conspiracy: Rediscovering Our Hidden Life in God (1998). San Francisco: Harper, ISBN 0-06-069333-9
• Hearing God: Developing a Conversational Relationship With God (1999). Intervarsity Press (USA), ISBN 0-8308-2226-7 (formerly titled In Search of Guidance: Understanding How God Changes Lives ISBN 006069520X)
• Putting on the Character of Christ (2002). Colorado Springs: NavPress, ISBN 1-57683-296-1
• The Great Omission: Reclaiming Jesus's Essential Teachings on Discipleship (2006). San Francisco: Harper, ISBN 0-06-088243-3
• Knowing Christ Today: Why We Can Trust Spiritual Knowledge.(2009).San Francisco: Harper, ISBN 978-0-06-088244-0