Born in Brooklyn, New York, in 1942, Giulio Maestro grew up in New York City's Greenwich Village. An avid cartoonist, Maestro's idols were Walt Disney and Walt Kelly, who was the creator of the popular “Pogo” comic strips. After writing to Kelly, Maestro received a personal letter that changed his life by validating his dream of becoming an artist. In high school, Maestro expanded his range beyond cartooning, and he went on to study art at New York's prestigious Cooper Union. For many years after graduation, Maestro worked in advertising doing layout and design. He missed drawing, however, and so turned his hand to illustration. While he began illustrating works written by other people, in 1971 Maestro wrote his first children's book, The Tortoise's Tug of War, a retelling of a South American variation of an African tale.
In his unbelievably varied and prolific career, Maestro has continued to write and illustrate his own books and illustrate those of others. He often works in collaboration with his wife, writer Betsy Maestro, and has also published several riddle books with their son, Marco Maestro. Maestro's work has been published in Great Britain, France, Germany, Spain, the Netherlands, and Japan. He enjoys woodworking, reading, gardening, traveling, and making jam.
The Maestros live and work in Old Lyme, Connecticut. They have two children.