American writer and illustrator of immensely popular children's books.

After undergraduate work at Dartmouth College, Hanover, N.H., and postgraduate work at Lincoln College, Oxford, and at the Sorbonne, Geisel began working for Life, Vanity Fair, and other publications as an illustrator and humorist. After service in the army during World War II, Geisel went into advertising for a time, was made an editorial cartoonist for PM newspaper in New York City, and eventually in 1958 founded Beginner Books, Inc., which in 1960 became a division of Random House.

Geisel's books were valued not only for their unique brand of humour but also for their contribution to the education of children. The books coined new nonsense words and animal characters that went far beyond the traditional primers. They include And To Think That I Saw It on Mulberry Street (1937), Horton Hatches the Egg (1940), How the Grinch Stole Christmas (1957), The Cat in the Hat (1957), Green Eggs and Ham (1960), and The Lorax (1971).

Geisel also made documentary films; Hitler Lives (1946) and Design for Death (1947, with his wife Helen Palmer Geisel 【d. 1967】), both won Academy Awards. His animated cartoon Gerald McBoing Boing (1951) also won an Academy Award. He designed and produced animated cartoons for television, many of them based on his books. From 1948, Geisel lived in La Jolla, Calif., where he annually conducted a children's workshop at the La Jolla Museum of Art.