Controllers from the UNSA union have gone on strike at Brest, Bordeaux and Aix-en-Provence airports as part of a four-day strike that began yesterday.
Workers at Nice and Marseille airports also went on strike today.
The dispute has arisen over working times and conditions, affecting all flights that use French air space.
Some 28 flights arriving or leaving Spain were cancelled today.
Some 18 were from Spanish airline Vueling.
Easyjet, Ryanair, Iberia and BA have also been affected.
All passengers who have flights up until Thursday are advised to check the status of them before travelling.