The book was well-received upon publication, variously lauded in reviews as "always affecting,"  having "broad appeal," and being full of "pathos and compassion."  Booklist reviewer Deborah Abbot says, "...this unusual novel magically weaves timely issues of homelessness, racial prejudice, and illiteracy into a complicated story rich in characters and details...an energetic piece of writing that bursts with creativity, enthusiasm, and hope." 
Reviewers noted that the theme of racism was uncommon for "middle readers". Criticism concentrated on Spinelli's choice of framing it as a legend, which Shoemaker calls a "cop-out,"  which frees him from having to make it real or possible. It has also been called "long-winded," and seeming like a "chalkboard lesson."
Awards and honors
Awards and honors for the book include:
- 1990: Boston Globe/Horn Book Award
- 1991: Carolyn Field Award, Newbery Medal (American Library Association)
- 1992: Charlotte Award, Dorothy Canfield Fisher Award, Flicker Tale Award, Indian Paintbrush Book Award, Rhode Island Children's Book Award
- 1993: Buckeye Children's Book Award, Land of Enchantment Award, Mark Twain Award, Massachusetts Children's Book Award, Nevada Young Readers' Award, Pacific Northwest Library Association Young Reader's Choice Award, Rebecca Caudill Young Reader's Book Award, West Virginia Children's Book Award, William Allen White Award
The U.S. National Education Association named Maniac Magee one of "Teachers' Top 100 Books for Children" based on a 2007 online poll. In 2012 it was ranked number 40 among all-time children's novels in a survey published by School Library Journal, a monthly with primarily U.S. audience.
Use for educational and research purposes
The book is popular in elementary schools as a historical-fiction novel. Many study units and teaching guides are available. including a study guide by the author. It has been used as a tool in scholarly work on childhood education and development. Fondrie cites it as an example in a discussion of how to bring up and discuss issues of race and class among young students. McGinley and Kamberlis use it in a study of how children use reading and writing as “vehicles for personal, social, and political exploration.”  Along the same lines, Lehr and Thompson examine classroom discussions as a reflection of the teacher’s role as cultural mediator and the response of children to moral dilemmas, and Enciso studies expressions of social identity in the responses of children to Maniac Magee.
In a less pedagogical vein, Roberts uses the character of Amanda Beale as an archetypical "female rescuer" in a study of Newbery books, and Sullivan suggests the book as being useful in discussions of reading attitudes and difficulties.