Guillaume de Sax (1889–1945) was a Belgian actor.
De Sax was born Guillaume Henri Robert de Segur Lamoignon in Belgium and died in France. He was married to the actress Cécile Sorel.
Partial filmography
Ernest the Rebel (1938)
Three Waltzes (1938)
I Was an Adventuress (1938)
Coral Reefs (1939)
Immediate Call (1939)
Angelica (1939)
Cristobal's Gold (1940)
Sins of Youth (1941)
Miss Bonaparte (1942)
The Lover of Borneo (1942)
No Love Allowed (1942)
Twisted Mistress (1942)
Colonel Pontcarral (1942)
Strange Inheritance (1943)
La Main du diable (1943)
Picpus (1943)
Vautrin (1943)
Farandole (1945)
The Eleventh Hour Guest (1945)