Henri Kellen had a promising start to his cycling career when he won the 1948 edition of the Grand Prix François Faber one-day race in his native Luxembourg. This, along with several other podium finishes in home races, earned Kellen a place on the Olympic team. At the London Games he competed in the road race but did not finish the course. One year later he won a stage at both the Tour de Luxembourg and the Flèche du Sud races. In 1950 Kellen entered the Tour de France as an independent competitor, finishing ninth on the second stage of the race, before abandoning the race after stage 11. Less than a month later, however, Kellen tragically died during a cycling race in Switzerland when he suffered heat stroke. He was 23-years-old.