Calvin O'Keefe is a major character in Madeleine L'Engle's Time Quartet series of books, and, as "Dr. Calvin O'Keefe", an important character in her O'Keefe series of young adult novels. In an interview released on the DVD of the TV adaptation of A Wrinkle in Time, L'Engle describes Calvin as "the boy that we all, all us girls want to meet. Not all of us are lucky enough to meet a Calvin, but I was. And I married mine."