Ludo Loos (13 January 1955 – 1 March 2019) was a Belgian professional road bicycle racer.

During the 1980 Tour de France Loos was able to escape in a solo breakaway during Stage 18, which was a major mountain stage. He was the first rider over all five climbs and won the stage finishing 5:19 ahead of the group of favorites which included his teammate Lucien Van Impe, Robert Alban, Joaquim Agostinho and eventual yellow jersey winner Joop Zoetemelk. Loos would finish eighteenth in that year's general classification and second in the mountains classification.

In the 1985 Vuelta a España, Loos collided with a dog, and broke a neck vertebra. This effectively ended his career as cyclist.

On 1 March 2019, Loos died following a long illness.^[1]