Donna Jo Napoli was born on February 28, 1948, in Miami, Florida, to parents Vincent Robert Napoli and Helen Gloria Napoli. Having vision problems as a young child, Napoli struggled to learn how to read. It was not until the age of 10 that Napoli overcame her vision problems and became interested in reading. When she finally began reading, she jumped into biographies and history books, such as A Tree Grows in Brooklyn (1943) and the works of Mary Renault. Through elementary and high school, Napoli traveled from school to school, as her father worked as a contractor, built their family new homes, and sold them soon after.

Napoli earned an AB in Mathematics, an MA in Italian Literature, and then a PhD in Romance Languages and Literature from Harvard University. During her junior year at Harvard, she married Barrow Ray Furrow. They eventually had five children: Elena, Michael, Nicholas, Eva, and Robert. In 1973, Napoli was a visiting scientist in Linguistics at the Massachusetts Institute of Technology.

Starting her career, Napoli lectured at Smith College, the University of North Carolina (Chapel Hill), Georgetown University, University of Michigan (Ann Arbor), and Swarthmore College. She has even lectured overseas at the University of Queensland (Australia), the University of Geneva (Switzerland), the University of the Witwatersrand (South Africa), and many more. At the University of Michigan, she received tenure and became a full-time professor in 1984. At the time of this writing, she is the head of the Linguistics Department at Swarthmore College, located near Philadelphia, Pennsylvania.

Despite never expecting to become a writer, Napoli discovered that writing was a way that she could express herself and it brought great joy into her life. Napoli's first publications came in linguistics. She wrote many acclaimed linguistic analyses, including Linguistics: Theory and Problems (1993). Her paper Syntax: Theory and Problems (1993), according to the Library of Congress, allows its readers to understand the fundamentals of articles written in different theories. Its goal is for readers to approach linguistics with an open mind. Likewise, Predication Theory: A Case Study for Indexing Theory (1989), from the Library of Congress, entails argument, predicate, and coindexing principles. The predicate is presented as a semantic primitive and the coindexing principles follow Noam Chomsky's 1986 notion of barriers. She is especially noted for her study of the linguistics of sign languages, a groundbreaking line of research for the field.

After losing a child to a miscarriage, Napoli became inspired to write for a younger audience. Her first children's book was The Hero of Barletta (1988). This book retold an old Italian myth, and after its release, Napoli began experimenting with more original narratives. One of these books was Flamingo Dream (2002), which is about a child dealing with her father's death. Napoli's favored themes of family and animals is also evident in Pink Magic (2005).

She often wrote novels with the help of her children, Robert and Eva. Robert Furrow aided her in writing the Sly the Sleuth series and Richard Tchen assisted her in Spinners. Eva Furrow, Shelagh Johnston, and Marie Kane are also writers with whom Napoli has worked closely.

Napoli writes about history, mysteries, music, and fairytales, typically receiving much critical acclaim. However, she has also received her fair share of criticism. The Magic Circle (1993) received some negative feedback for its discussion of witchcraft for a young adult audience. When the Water Closes Over my Head (1994) also received bad reviews due to the language she used; many teachers thought it was inappropriate for young readers.

Many of Napoli’s books have received outstanding awards. Among her picture books and early reader books, Albert (2001) captured most of the attention, winning the Kentucky Bluegrass Award, Los Angeles Times Best Book, New York Public Library Children's Books 2001, and other awards. Napoli's The Prince of the Pond (1992) received the most recognition among her elementary and middle school readers. It received over 10 awards, including the New Jersey Reading Association's M. Jerry Weiss Book Award of 1997, 100 Best Children's Books of 1992, Outstanding Merit, and book of the month in the Philadelphia Children's Reading Round Table. Napoli's books have been translated into Spanish, German, Chinese, Japanese, Danish, Dutch, Hebrew, Korean, and other languages.

At the time of this writing, Donna Jo Napoli has written over fifty books. She lives with her husband and continues teaching at Swarthmore while writing books for all ages.