Newman played at the center position for Cornell University from 1904 to 1906. He was selected as a first-team All-American by Caspar Whitney in 1906. Newman played for the Cornell football team during all three years in which Glenn "Pop" Warner was the head coach. Newman also rowed in the bow seat on Cornell's varsity crews from 1906 to 1907 that won Intercollegiate Rowing Association championships. In 1927, Newman was selected as the second-team center on Cornell's all-time football team. In supporting the selection, the New York Sun wrote: "Although Bill Newman never weighed 170 pounds, he had the reputation of being the strongest man physically who ever attended Cornell. ... Although he attained his greatest fame as an oarsman, Newman was a bull on the gridiron with a punishing drive that carried opponents back to China." For his contributions to championship teams in both football and rowing, Newman was tapped for the Quill and Dagger society and the Cornell Alumni News in 1933 called him "one of Cornell's all time athletic heroes."
Newman graduated from Cornell in 1907. That fall, Warner took over as the head football coach of the Carlisle Indian Industrial School. Warner hired Newman as his line coach at Carlisle. Newman was an assistant coach at Carlisle in 1907. Newman later served as head coach at Georgetown in 1908 and 1909. Newman was inducted into the Cornell University Hall of Fame in 1978. In 1913, Newman returned to Cornell as an assistant football coach.