Félix Lucien Roger Debax (28 September 1864 – 25 August 1914) was a French army officer and Olympic fencer.
Born in Toulouse, Debax entered the army as an officer-candidate at the age of 18.
After service with the infantry (where he was promoted to the rank of captain), he became attached to the army gymnastics school (Ecole Normale de Gymnastique) in 1889.
He was transferred back to the infantry for two years from 1893, before returning to the ecole.
Debax remained a gymnastics teacher until 1901 during which time he competed as a fencer at the 1900 Summer Olympics in Paris.
After Debax left the ecole he was transferred to the infantry once again, though he published books on the teaching of gymnastics and fighting with the bayonet, and also studied at the Stockholm Gymnastics Institute.
Promoted to chef de bataillon Debax was killed on 25 August 1914, fighting the German forces at Saint-Maurice-sous-les-Côtes during the first month of the First World War.