Activists staged a mock marriage at the site, with the airport represented as a bride who unsuccessfully tries to flee privatisation, her unwanted groom.
Wearing Sunday suits and early 20th century hats for the event, the activists-cum-actors handed postcards out to travellers, urging them to send them to President Francois Hollande in protest.
One side of the card reads: "Privatisation seriously harms your health, and the common good of the people of Toulouse."
The other side carries a message from critics of the sale to Hollande, urging him to reconsider the divestment.
Toulouse-Blagnac Airport is France's sixth-busiest.