The Secret of the Selenites (French: Le secret des sélénites) is a 1984 French animated comedy film directed by Jean Image, his last film before he died 5 years later. It is also known as Moon Madness in the United States and Moontrek in the United Kingdom.

The film is loosely based on the novel Baron Munchausen's Narrative of his Marvellous Travels and Campaigns in Russia (1785) by Rudolf Erich Raspe. Baron Munchausen, the titular protagonist, is a fictional German nobleman. Raspe based the character on a real-life Freiherr (Baron), Hieronymus Karl Friedrich, Freiherr von Münchhausen (1720–1797). The fictional Baron of the novel is a retired soldier and world traveler, who narrates tall tales about his past. In one of his best-known stories, the Baron travels to the Moon.