Father Maynard J. Geiger, O.F.M., Ph.D. (1901–1977) was a Roman Catholic priest and clerical historian of the Franciscan Order. Reverend Geiger wrote extensively on various aspects of the California mission system, and is most well known for his biography of Junípero Serra, the first "Father Presidente" of the Alta California missions. He was a tireless apologist for the mission system and the evangelization of the native populations, choosing to highlight through his scholarship the achievements and dedication of the friars of California.