Clifford Douglas "Pop" Bliss (July 16, 1870 – March 26, 1948) was an American football player and coach. He served as the head football coach at Stanford University, Haverford College, and the University of Missouri, compiling a career college football record of 15–6–1. Bliss played football at Yale University as a halfback alongside his brother, Laurie Bliss, who went on to coach at the United States Military Academy and Lehigh University.