Chatham is Community Area 44 of 77 on the city's official roster of neighborhood areas. Chatham's sub-neighborhoods include East Chatham, West Chatham and West Chesterfield.

Chatham's approximate boundaries are the RR tracks north of Burnside Ave (9400 S) and 91st St north to 79th St, and west from the IC RR tracks to RR tracks, Stewart Ave (400 W), and RR tracks west of Parnell Ave (532 W) from 83rd St to 79th St.

ZIP codes: 60619, 60620.