Trevor Reed, 19, was arrested shortly after the boy was shot in the leg in the 800 block of East 89th Street around 2:55 p.m., Chicago police said.
The boy was taken to the University of Chicago Medical Center in good condition, police said.
A gun was recovered at the scene and Reed was taken in for questioning, police said. He was later charged with aggravated use of a weapon and possession of a controlled substance.
Reed was to appear in bond court Tuesday.
The boy was among nearly a dozen people shot over four hours in Chicago late Monday afternoon and early evening.
