Interior Minister Gerald Darmanin said on X that the assailant had been arrested and the soldier's wounds were not life threatening.
France is on its highest state of alert. The soldier was deployed within Operation Sentinelle, a 3,000-strong unit which patrols sites such as railway stations, places of worship, schools and theatres.
Earlier this year, Prime Minister Gabriel Attal placed an additional 3,000 troops on standby for Sentinelle.
The attack took place at Paris' Gare de l'Est.
The assailant's motive was not immediately clear.