One Fish, Two Fish, Red Fish, Blue Fish is a 1960 children's book by Dr. Seuss. As of 2001, over six million copies of the book had been sold, placing it 13th on a list of "All-Time Bestselling Children's Books" from Publishers Weekly. Based on a 2007 online poll, the United States' National Education Association labor union listed the book as one of its "Teachers' Top 100 Books for Children".

Theodor Seuss Geisel was an American children's author and cartoonist. He is known for his work writing and illustrating more than 60 books under the pen name Dr. Seuss. His work includes many of the most popular children's books of all time, selling over 600 million copies and being translated into more than 20 languages by the time of his death.