Stephon Williams approached the girl in the 1200-block of West 79th Street at about 10:06 p.m. and exposed his genital area and made an inappropriate remark, police said.
Police located Williams a short time later in the 8000-block of South Racine Avenue and took him into custody.
On Sunday, police announced Williams has been charged with one felony count of exploiting a child under 13 and a felony count of indecent solicitation. He is scheduled to appear in bond court Sunday.