Orthodoxy is a book by G. K. Chesterton that has become a classic of Christianity. In the book's preface Chesterton states the purpose is to "attempt an explanation, not of whether the Christian faith can be believed, but of how he personally has come to believe it." Chesterton presents an original view of Christian religion. He sees it as the answer to natural human needs, the "answer to a riddle" in his own words, and not simply as an arbitrary truth received from somewhere outside the boundaries of human experience.

Orthodoxy was influential in the conversion of Theodore Maynard to Roman Catholicism as well as in the ordination of Canon Bernard Iddings Bell. In the magazine, The Atlantic, critic James Parker recommends the book thusly: "If you've got an afternoon, read his masterpiece of Christian apologetics Orthodoxy: ontological basics retailed with a blissful, zooming frivolity, Thomas Aquinas meets Eddie Van Halen." Chesterton chose the title, Orthodoxy, to focus instead on the plainness of the Apostles' Creed, though he admitted the general sound of the title was "a thinnish sort of thing."

This case laminate collector's edition includes a Victorian inspired dust-jacket.