George Derek Ibbotson MBE (17 June 1932 – 23 February 2017) was an English runner who excelled in athletics in the 1950s. His most famous achievement was setting a new world record in the mile in 1957.

Ibbotson was born in Huddersfield in the West Riding of Yorkshire, and studied at King James's Grammar School, Almondbury. He was of the generation that included other great British milers such as Roger Bannister, Chris Brasher and Christopher Chataway. He was the junior champion in Britain in 1951.

After service in the Royal Air Force, Ibbotson returned to competition. In 1956 at Melbourne, he won a bronze medal in the 5,000 metres. After the games, Ibbotson focused on the mile, which was probably an error. Ibbotson began the 1957 season running in mile races, as a 5,000m or 3 mile runner would often do in the early part of the racing season - to race at a faster pace than he would need in those longer distances. After he had run a particularly fast mile at a Glasgow meeting, an experienced athletics official told the BBC that while it was a very good time, he and many others felt that Ibbotson’s greater potential was over 5,000m or 3 miles. In a race dubbed "mile of the century", Ibbotson won, probably because Delaney, the 1,500m champion at Melbourne the previous year, was boxed in at a crucial point on the final lap. The time was a new world record, taking 0.8 of a second off John Landy's time of 3.58 min set in 1954. Ibbotson continued competing in mile races throughout the season as well as some longer distance events - and ended the season exhausted. It was not just the number of races but the faster pace at which they were run.

Ibbotson never found the same form again. He represented England in the Empire Games at Cardiff in 1958, finishing tenth in the 3 miles. Ibbotson soldiered on and in 1960, in a bid to enter the Rome Olympics, he copied Gordon Pirie who, when he was struggling for form, increased his racing and took part in shorter races than usual, because it was good speed training. Ibbotson was not so successful and was not selected.

He was appointed Member of the Order of the British Empire (MBE) in the 2008 New Year Honours for services to athletics. In 2011, he was inducted into the England Athletics Hall of Fame.

He died in Wakefield in 2017, aged 84.