In 2006, Mere Christianity was placed third in Christianity Today's list of the most influential books amongst evangelicals since 1945. The title has influenced Touchstone Magazine: A Journal of Mere Christianity and William Dembski's book Mere Creation. Charles Colson's conversion to Christianity resulted from his reading this book, as did the conversions of Francis Collins, Jonathan Aitken, Josh Caterer and the philosopher C. E. M. Joad.
A passage in the book also influenced the name of contemporary Christian Texan Grammy-nominated pop/rock group Sixpence None the Richer. The phrase, "the hammering process" was used by Christian metal band Living Sacrifice for the name of their album The Hammering Process. Metalcore band, Norma Jean, derived the title of their song "No Passenger: No Parasite" from the section in the book in which Lewis describes a fully Christian society as having "No passengers or parasites".