Judy Blume was born in Elizabeth, New Jersey, on February 12, 1938, to Rudolf and Ester Sussman. Blume moved to Miami Beach with her mother and older brother, David, when she was in third grade to aid his recovery from a kidney infection; her father remained in New Jersey to continue running his dentistry practice.

She married John Blume in 1959, having two children with him, a son Larry and a daughter Randy, and they also have one grandchild named Elliot.

In 1961, Blume graduated with a B.S. in Education from New York University, an institution which would name her a Distinguished Alumna thirty-five years later. John and Judy Blume divorced in 1975 and she married and divorced once again before meeting George Cooper, whom she married in 1987; through this marriage, Blume gained a stepdaughter, Amanda. Blume and Cooper also have a grandson and currently reside in Key West and New York City.

A lifelong avid reader, Blume first began writing when her children began preschool, and published her first book, The One in the Middle Is the Green Kangaroo, in 1969. The decade that followed proved to be her most prolific, with 13 more books being published, including many of her most well-known titles, such as Are You There God? It's Me, Margaret. (1970), Tales of a Fourth Grade Nothing (1972), Otherwise Known as Sheila the Great (1972), and Blubber (1974).

After publishing novels for young children and teens, Blume tackled another genre...adult reality and death. Her novels Wifey and Smart Women shot to the top of The New York Times best-seller list. Wifey has become a bestseller, with over 4 million copies sold to date. Her latest and third adult novel Summer Sisters (1998) was widely praised and has sold more than 3 million copies. It spent 5 months on The New York Times Bestseller list, with the hardcover reaching #3 and the paperback spent several weeks at #1.

Blume has won more than ninety literary awards. In 2004, she was awarded the National Book Foundation Medal for Distinguished Contribution to American Letters. In 1996 the American Library Association selected Blume for its Margaret A. Edwards Award for her contributions to young adult literature. Blume received the Library of Congress Living Legends award in the "Writers and Artists" category in April 2000 for her significant contributions to America's cultural heritage. Blume has also had several books to appear on the list of top all-time bestselling children’s books. Some of her books have become made for television movies, but she has had little success here.

She once drew some pictures for the book The One in the Middle is the Green Kangaroo. She threatened to haunt her children if they were ever to publish the pictures after her death, saying "I have kept them in the closet. Colored them. With little colored pencils. Fastened them with little brass fasteners like I was still in school. I told my children that if they try to publish them after I die I will come back and haunt them."

Blume is also an advocate for teachers reading aloud to their students. She gets an uncountable amount of mail from students and adults whose teachers read aloud to them. Blume herself has specific memories of being read aloud to by her teachers. Blume believes that if teachers would take the time to introduce good books to students, perhaps there would not be as many reluctant readers.

Though light in tone, many of Judy Blume’s books deal with difficult issues for children, including questioning the existence of God, friendship, religion, divorce, body image, and sexuality. However, Blume states that she does not set out to tackle these issues when writing. She begins with a character, sometimes a character and a situation.

Fans of Blume's novels have praised her use of real-life settings, ambivalent endings and gentle humor. Her allegedly ambiguous treatment of moral issues made her at one time a regular target of school library censors and the religious right. Her books are still often challenged in school libraries; in fact, Forever was the second most challenged book of 2005, according to the American Library Association. When her books first came under attack, she went through a variety of emotions: scared, frightened, alone, and angry. In an interview with Publisher’s Weekly, Blume states that the fear of censorship can be contagious. In another interview, Blume tells Judy Freeman, children’s literature consultant and author, that the sadness came from a sadness for children who may not be allowed to read banned books. She says, “It says to them, “There’s something in this book we don’t want you to know about, something we don’t want to discuss with you.’” She is recognized as one of the most banned children's authors in the United States which eventually led her to edit a collection of short stories about censorship (Places I Never Meant to Be). Despite ardent attempts at censorship, Blume's young adult novels and books for children have sold 80 million copies worldwide.

Perhaps one of her most censored and challenged books is Are You There God? It’s Me, Margaret. (1970), which is considered to deal with many 'rite of passage' topics for young, pre-teen girls. This book is about an eleven year old girl, Margaret Simon, who is growing up with no organized religion (her father is Jewish and her mother Christian). However, she does seem to have a close relationship with God. She views Him as her friend and confidant, someone she talks to when she cannot seem to talk to anyone else about important issues in her life. When assigned a yearlong independent project at school, Margaret chooses to study people’s beliefs. This proves to be a weighty assignment for Margaret. In her quest to complete the project and find out more about other’s beliefs, Margaret discovers a lot about herself as well. Through serious yet sometimes comical situations, the book also deals with several other taboo topics: Margaret having to buy her very first bra; having her first period and having to deal with sanitary napkins; jealousy over other girls having more womanly figures than hers; and liking boys. Margaret learns to better understand and cope with these issues from talks with her mother, grandmother, friends, and of course, God. This book deals openly with sexuality and religion, which makes it one of the most challenged books in America. On the list of the top 100 most challenged books between 1990 and 1999 at the American Library Association, Are You There God? It’s Me, Margaret., falls at number sixty. In several interviews, Blume tells the story of receiving a phone call from a woman who harassed her and called her a communist for writing this book. Blume jokes that she does not know whether she received this accusation because of how the book dealt with religion or because of how it dealt with sexuality.

In her efforts to preserve for young readers intellectual freedom in literature, Blume joined the National Coalition Against Censorship, which comprises fifty not-for-profit organizations that come together to fight censorship. Judy Blume has also founded or is closely affiliated with several other organizations regarding children’s literature and censorship, including, The Kids Fund, The Authors Guild (she serves, in 2010, as the group's vice president), the Society of Children’s Book Writers and Illustrators, and the Key West Literary Seminar. Blume is also the editor for a collection of short stories, Places I Never Meant To Be, Original Stories by Censored Writers. Blume also tells Freeman that censorship is not getting any better. There has been a rise in challenged books over the years. Blume urges teachers and writers who feel passionately about censorships to speak out and share their voice on the subject.