John Fullerton MacArthur Jr. (born June 19, 1939) is an American Protestant pastor and author known for his internationally syndicated Christian teaching radio and television program Grace to You. He has been the pastor of Grace Community Church, a non-denominational church in Sun Valley, California since February 9, 1969. He is currently the chancellor emeritus of The Master's University in Santa Clarita and The Master's Seminary.

MacArthur is a strong proponent of expository preaching, and has been acknowledged by Christianity Today as one of the most influential preachers of his time. MacArthur has written or edited more than 150 books, most notably the MacArthur Study Bible, which has sold more than one million copies, receiving a Gold Medallion Book Award.