Dallas McCord "Mack" Reynolds was an American science fiction writer. His pen names included Dallas Ross, Mark Mallory, Clark Collins, Dallas Rose, Guy McCord, Maxine Reynolds, Bob Belmont, and Todd Harding. His work is noteworthy for its focus on socioeconomic speculation, usually expressed in thought-provoking explorations of Utopian societies from a radical, sometime satiric, perspective. He was a considerably popular author from the 1950s to the 1970s, especially with readers of science fiction and fantasy magazines.