The 2003 UCI Road World Championships took place in Hamilton, Ontario, Canada, between October 7 and October 12, 2003.

The event consisted of a road race and a time trial for men, women, men under 23, junior men and junior women.

David Millar was handed a two-year ban and stripped of his world time trial title by the British cycling federation for taking the banned performance enhancer EPO.

[1] Following this disqualification, the UCI declared Michael Rogers as the winner with the silver medal going to Uwe Peschel and the bronze to Michael Rich.

[2] Jeannie Longo rode alone ahead of the pack for most of the women's road race but was passed approximately 500m from the finish.