The soldier, named as First Class Legionnaire Kévin Clément, was involved in a mission against armed terrorist groups, the French army's general staff said in a statement on Tuesday.
"Challenged at close range, the leading unit retaliated and put two jihadists out of action," the statement added.
Clément was wounded in action on Monday but died after being evacuated by helicopter to a medical unit in Gao.
Last Friday, another legionnaire from the same regiment died of wounds he suffered on 23 April when an improvised explosive device was set off.
Forty-three French soldiers have been killed in the Sahel region since the country deployed troops in 2013 to help local forces battling jihadist.
Mali is struggling to combat an Islamist insurgency that has claimed thousands of lives since it erupted in 2012.
Thousands of French and UN personnel have been operating in the region but they have failed to stop the conflict engulfing central Mali and spreading to neighbouring Burkina Faso and Niger.
