Northbrook, village, Cook County, northeastern Illinois, a suburb of Chicago, near Lake Michigan; incorporated as a village 1923. It is primarily residential and has insurance-company offices and some manufacturing industries. A botanical garden is nearby. The community, settled in 1838, was called Shermer's Station after the arrival of the railroad in 1871. The present name was chosen in a contest in 1922. Population 30,778 (1980); 32,308 (1990); 33,435 (2000).