Marcel Ichac, born October 22, 1906 in Rueil-Malmaison (Seine-et-Oise) and died April 9, 1994 in Ézanville (Val-d'Oise), was a French filmmaker, photographer, explorer, and mountaineer. He was the brother of Pierre Ichac (1901-1978).

"A great master of documentary filmmaking," according to historian Jean Tulard, Marcel Ichac is particularly considered "the greatest filmmaker specializing in mountain films in France and undoubtedly in the world" of his generation by Georges Sadoul. Initially a skier and mountaineer, a great witness to French mountaineering, Marcel Ichac went on to become, through the diversity of the spaces he explored, the filmmaker of French exploration in the 1930s and 1950s (the first two French expeditions to the Himalayas in 1936 and 1950, scuba diving with Jacques-Yves Cousteau, Greenland with Paul-Émile Victor, the world's first caving documentaries, notably with Norbert Casteret, etc.).

Marcel Ichac revolutionized documentary filmmaking with his desire to place the viewer at the heart of the action, obsessing over authenticity. This required, beyond accompanying the athlete in his efforts, technical innovations (the widespread use of lightweight cameras, whereas the cameras of the time were generally heavy and fixed), artistic innovations (the subjective camera, mounted on skis, carried on the shoulder, etc., shooting from the mountaineer's perspective), and narrative innovations. Marcel Ichac is considered a pioneer of "cinema verité" and docu-fiction. Beyond that, Marcel Ichac played a pioneering role, both in the technical field (notably with the production of the first French film in CinemaScope, etc.), institutions (founding the Group of Thirty to promote short films), and individuals (launching Jacques Ertaud, Jean-Jacques Languepin, Gérard Oury, Jean-Louis Trintignant, and Robert Enrico into the film industry).

Marcel Ichac received the highest accolades in world cinema (an Oscar in Hollywood, awards at the Cannes Film Festival and the Venice Film Festival, not to mention festivals specializing in mountain and exploration cinema). Marcel Ichac boasted over a hundred ascents to his name as a mountaineer. He was a member of the Explorers Club of New York, the French Society of Explorers, and the Groupe de Haute Montagne (GHM), as was his wife, Gabrielle Ichac-Lartigue, herself an experienced mountaineer.

When high mountain climbing was closed to him at the age of 70, Marcel Ichac took up running and long-distance walking. He regularly competed in the Millau 100K (France) and the New York City Marathon, where he won first place in the Diamond Age category for those over 80 in 1986.