Curtis was born in Flint, Michigan on May 10, 1953 to Dr. Herman Elmer Curtis, a chiropodist, and Leslie Jane Curtis, an educator. The city of Flint plays an important role in many of Curtis's books. One such example is Bucking the Sarge, which is about a fifteen year old boy named Luther T. Ferrel, who is in a running battle with his slum-lord mother. Curtis is an alumnus of the University of Michigan-Flint.

Curtis is the father of two children, Steven, an ensign in the United States Navy, and Cydney, a college student and accomplished pianist. His third child is expected to make an appearance in 2011. Christopher modeled characters in Bud, Not Buddy after his two grandfathers—Earl “Lefty” Lewis, a Negro league baseball pitcher, and 1930s bandleader Herman E. Curtis, Sr., of Herman Curtis and the Dusky Devastators of the Depression.

Curtis moved to Detroit, Michigan in January, 2009