Theodor Seuss Geisel (March 2, 1904-September 24, 1995) was an American writer and cartoonist most widely known for his children's books written under the pen names Dr. Seuss, Theo. LeSieg and, in one case, Rosetta Stone. He published 44 children's books. Some books are The Cat in the Hat, Green Eggs and Ham, The Lorax, Horton Hears a Who!, One Fish Two Fish Red Fish Blue Fish, Hop on Pop, Dr. Seuss' ABC, and How the Grinch Stole Christmas!. His books were often characterized by imaginative characters, rhyme, and frequent use of trisyllabic meter.

Geisel was born in 1904 in Springfield, Massachusetts, and died in 1995 in San Diego, California. March 2 is Read Across America Day, Dr. Seuss' birthday. Over the course of his long career, Geisel wrote over 60 books.

From 1971 to 1989, Geisel wrote 7 seven television specials which were aired on CBS and produced by Warner Bros. Animation: Horton Hatches the Egg (1971), The Lorax (1972), Dr. Seuss on the Loose (1977), Pontoffel Pock, Where Are You? (1980), The Grinch Grinches the Cat in the Hat (1983), and The Butter Battle Book (1989).

In 2000, a film adaptation of The Grinch starred Jim Carrey. In 2003, a film adaptation of The Cat in the Hat featured Mike Myers as the title character. In 2008, a film adaptation of Horton Hears a Who! was released. The film adaptation of The Lorax is coming in 2011.

The Wubbulous World of Dr. Seuss aired from 1996 to 1997. Gerald McBoing-Boing aired from 2005 to 2007. The Cat in the Hat Knows a Lot About That! is a 2010 children's educational animated cartoon series on PBS Kids.