Born in Tooting, London, Hill started out as a long distance runner, winning the British AAA championships over 4 miles in 1910. Hill served with the Royal Flying Corps in France during World War I.
After the war, Hill returned as a middle-distance runner. Coached by Sam Mussabini (coach of 100 m Olympic Champions Reggie Walker and Harold Abrahams), he won the 880 yd and 1 mile at the 1919 AAA championships and then equalled the British record of 4:16.8 for 1 mile. He nearly was not selected for the Olympics the following year, the selectors considering the 31-year-old Hill too old. Finally, he was allowed to take part at the Olympics, which were held in Antwerp, Belgium. He made the final in the 800m, which was a closely contested race. In the end, the 31-year-old Hill beat American Earl Eby for the gold, setting a British record of 1:53.4 on a slow track.
Two days later, Hill completed the middle distance double by winning the 1500m as well, thus completing a "double" not replicated by a British athlete until Kelly Holmes at the 2004 Olympics. Helped by his compatriot, Philip Baker (who would receive the Nobel Peace Prize in 1959), he won comfortably, with Baker in second in a time of 4 min. 01.8 sec. Hill also competed in the 3000m team race event, in which the British team finished second, earning Hill's third Olympic medal.
Hill won the 1921 AAA mile championship in a British record of 4 min. 13.8 sec, this was 1.2 seconds outside the world record and the second fastest amateur time ever. Hill ended his running career in 1921 and became a coach himself, his most famous protégé being Sydney Wooderson. He emigrated to Canada shortly after World War II, and died there in 1969.