Julienne Marie Louise Aisner (née Simart; 30 December 1899 – 15 February 1947[1]), code named Clair, was an agent in France of the United Kingdom's clandestine Special Operations Executive (SOE) organization during World War II.

The purpose of SOE was to conduct espionage, sabotage, and reconnaissance in countries occupied by the Axis powers, especially Nazi Germany.

[2] When World War II began in 1939, her husband was called into the army and captured, but escaped and made his way to the United States where he would work as a technical adviser on the film Casablanca.

The job of Dericourt was to find landing fields and arrange receptions or departures for SOE agents arriving by air.

[5] Aisner assisted in Déricourt's first operation, the reception of agents landing in two Westland Lysander aircraft which came down in a farm field near Poitiers on the night of 17–18 March 1943.

[6] Aisner's usual job was to find safe houses in Paris for arriving or departing SOE agents and also to produce or obtain false identity documents for them to use.

Déricourt and Aisner were not arrested and continued air operations with a steady flow of agents coming to France and returning to England.

In August 1943, Aisner, with SOE approval, bought a small restaurant in Paris called the Cafe Mas which was used as a center for messages and contacts with agents.