He dropped out of high school at the age of 17 to serve in World War I. After serving briefly overseas as an ambulance driver, Disney returned in 1919 to Kansas City for an apprenticeship as a commercial illustrator and later made primitive animated advertising cartoons. By 1922, he had set up his own shop.

Initial failure sent Disney to Hollywood in 1923, where in partnership with his loyal elder brother Roy, he managed to resume cartoon production. His first success came with the creation of Mickey Mouse in Steamboat Willie. Steamboat Willie was the first fully synchronized sound cartoon and featured Disney as the voice of a character first called "Mortimer Mouse." Disney's wife, Lillian, suggested that Mickey sounded better and Disney agreed.

Living frugally, he reinvested profits to make better pictures. His insistence on technical perfection and his unsurpassed gifts as story editor quickly pushed his firm ahead. The invention of such cartoon characters as Mickey Mouse, Donald Duck, Minnie, and Goofy combined with the daring and innovative use of music, sound, and folk material (as in The Three Little Pigs) made the Disney shorts of the 1930s a phenomenon of worldwide success. This success led to the establishment of immensely profitable, Disney-controlled sidelines in advertising, publishing, and franchised goods, which helped shape popular taste for nearly 40 years.

Disney rapidly expanded his studio facilities to include a training school where a whole new generation of animators developed and made possible the production of the first feature-length cartoon, Snow White (1937). Other costly animated features followed, including Pinocchio, Bambi, and the celebrated musical experiment Fantasia. With Seal Island (1948), wildlife films became an additional source of income.

In 1954, Disney successfully broke into television. By the time of his death, the Disney studio's output amounted to 21 full-length animated films, 493 short subjects, 47 live-action films, seven True-Life Adventure features, 330 hours of Mickey Mouse Club television programs, 78 half-hour Zorro television adventures, and 280 other television shows.

On July 18, 1957, Disney opened Disneyland, a gigantic projection of his personal fantasies in Anaheim, California, which has proved the most successful amusement park in history with 6.7 million people visiting it by 1966. The idea for the park came to him after taking his children to other amusement parks and watching them have fun on amusement rides. He decided to build a park where the entire family could have fun together. In 1971, Disney World, in Orlando, Florida, opened. Since then, Disney theme parks have opened in Tokyo and Paris.