Oak Brook is located in northeastern Illinois in DuPage County west of Chicago and just northeast of Downers Grove. The Interstate 88/Interstate 294 interchange is on the city's northern edge. The population estimate for July 1, 1998 was 9,428, an increase of 341 since 1990.
Some of the town's annual events include the St. Andrew's Highland Games usually held the 3rd Saturday in June and the "Autumn Festival" held on the 1st weekend in October.
For those seeking post-high school education, the town is home to Keller Graduate School of Management.