An armed teenager released his hostages after a siege lasting nearly five hours in Blagnac, a suburb of Toulouse, on Tuesday.
Four people were taken hostage at a newsagents at about 4.20pm local time (14:20 GMT).
One hostage was released at about 8pm (18:00 GMT), accompanied by riot police and elite RAID officers.
The hostage taker was 17 years old, according to reports, and had purported links to the Yellow Vest movement. He apparently fired three shots in the air and demanded to speak to a negotiator, despite not sharing a claim.