Born in Strathroy, Ontario, Orton was paralysed when he fell out of a tree when a child. He regained his mobility at age twelve. Orton did his undergraduate studies in at the University of Toronto, before switching to the University of Pennsylvania in 1893. By then, he was already one of the top middle-distance runners in North America. He won national titles in Canada, the United States and the United Kingdom, in the one-mile, two-mile and steeplechase distances. Orton's one-mile time of 4:21.8 in 1892 stood as a Canadian record for 30 years. His total number of wins is reported to be 121.
Orton received his Ph.D. in 1896, but remained active in his sport. The crown on Orton's career might have been the 1900 Summer Olympics, held in Paris. Orton competed in three events: two steeplechase competitions and the 400 m hurdles. He won the gold medal in the 2500 m steeplechase and later won a bronze medal in the 400 m hurdles—collecting all of the medals won by Canada at the games. He placed fifth in the 4000 m steeplechase.
In addition to his career in athletics, George W. Orton was a very good soccer player and also played hockey and cricket during his time in Philadelphia. While attending the University of Toronto he played soccer for the 'Varsity' team in the Toronto Football League and was chosen for the Toronto all-star team that played an all-star team from the New England states on June 14, 1891. In 1910 he played centre half for the Philadelphia all-stars against the New York all-stars In Haverford, Pennsylvania, and in 1923, at the age of 50 was playing soccer for Merchantville in the Philadelphia league. He was a member of the Merion and Belmont Cricket Clubs of Philadelphia, the New York Athletic Club, the Pennsylvania Athletic Club, the University of Pennsylvania Track Club and a former secretary of the Rose Tree Fox Hunting Club of Media, Pa. Dr. Orton was also a member of the American Academy of Poets.