The LeO 451s were used by France, Germany, and Italy.
Start of War
At the start of the war in 1939, there were only 10 LeO 451s in the Armée de l'Air.
Only five of the LeO 451s were operation by September 1939.
The GB I/31, GB I/12, and GB II/12 were the first units equipped with the LeO 451s. By May 1940 these were still the only units that had the LeO 451.
After the Germans invasion they LeO 451s were used for low level ground support. It was a task for which they were ill suited and resulted in heavy losses.
The LeO 451s were also used in bombing missions in Germany and northern Italy.
There were 222 LeO 451s available at the start of the Battle of France. Out of the 373 LeO 451s delivered by June 1940, 150 were lost.
After the Fall of France
Once France fell production still continued in the unoccupied zone. 150 / 225 LeO 451s were completed. They were used in North Africa and Syria with the Vichy forces and some of these were used against the Allies.
Seized by Germans
In November 1942 the Germans took over the unoccupied zone of France and seized ~90 / 94 LeO 451s. These were used as transports. Others were given to the Italian Air Force.
Seized by Allies
Some LeO 451s were used by the USAAF and RAF as transports.
Surviving aircraft were used by the French well into the 1950s. In September 1957 the last two LeO 453s were withdrawn from service.