Keith John Cullen (born 13 June 1972 in Ilford, Greater London) is a male long-distance runner from England, who represented Great Britain at the 2000 Summer Olympics in the men's marathon.
He finished in 19th place, clocking 2:16:59.
Four years earlier, in Atlanta, United States, he was eliminated in the semi-finals of the men's 3000 metres steeplechase.
He is now a Graphic Designer living in North London.