Mark David Hylton (born 24 September 1976 in Slough, England) is a former British 400 metres sprinter.
Hylton won a silver medal in the relay at the 1996 Summer Olympics in Atlanta.
He tested positive for nandrolone in 1999, but a two-year ban was overturned following an appeal which revealed errors in the testing of his sample.
One aspect of the test showed a level of nandrolone at three nanograms per millilitre (one nanogram above the maximum limit), but flaws in other aspects saw the ban dismissed due to reasonable doubt.