Robert Cormier was born to Geoffrey Leonard and Irma Cormier, in Leominster, Massachusetts, United States, in the French-Canadian section of the town called French Hill. He was the second of eight children. His family moved frequently to afford rent, but never left his hometown. Even when he was much older and owned a summer home, it was still 19 miles away from Leominster. Cormier attended a private Catholic school, St. Cecilia's Parochial School. He began writing when he was in the first grade. He was praised at school for his poetry. He first realized his aspiration to become a writer during his year in 7th grade, when he was encouraged by a nun to write a poem. He attended Leominster High School, graduating as the president of his class. As a freshman at Fitchburg State College, he had his first short story published when a college professor, Florence Conlon, sent one of his stories to The Sign, a national Catholic magazine, without his knowledge for $75. Cormier began his professional writing career scripting radio commercials and went on to become an award-winning journalist. Even though he became widely known, he never stopped writing for his local newspaper, the Fitchburg Sentinel.

Cormier became a full-time writer after the success of his first novel for teenagers, The Chocolate War, followed by others such as I Am the Cheese and After the First Death. He was concerned with the problems facing young people in modern society, and this concern was reflected in his novels. He soon established a reputation as a brilliant and uncompromising writer. Included in his awards is the Margaret A. Edwards Award of the Young Adult Services Division of the American Library Association. This award is presented in recognition of those authors who provide young adults with a window through which they can view the world, and which will help them to grow and understand themselves and their role in society.

In a few of his books, Cormier's hometown of Leominster became the fictional town of Monument, and French Hill became Frenchtown.

Due to its language and sexual references, The Chocolate War has been challenged in various libraries and schools. In addition to language, the book also depicted secret societies and anarchic students. Between 1990 and 2000, it was rated as the fourth most challenged book according to the American Library Association.

Listed by publication date

Novels

• Now and At the Hour (1960)
• Mrs. Riley is a Bad Teacher (1962) (unpublished? manuscript only?)
• A Little Raw on Monday Mornings (1963)
• Take Me Where the Good Times Are (1965)
• The Chocolate War (1974)
• I Am the Cheese (1977)
• After the First Death (1979)
• The Bumblebee Flies Anyway (1983)
• Beyond The Chocolate War (1985)
• Fade (1988)
• Other Bells for Us to Ring (1990) (Published in U.K. in 1991 under the title Darcy)
• We All Fall Down (1991)
• Tunes for Bears to Dance To (1992)
• In the Middle of the Night (1995)
• Tenderness (1998)
• Heroes (1998)
• The Rag and Bone Shop (2001)

Collections

• Eight Plus One (1980)
• The Moustache (1974)
• Frenchtown Summer (1999)

Nonfiction

• I Have Words to Spend (1991)