The 26-year-old former reality TV star was escorted to a police station after crossing into Evanston from Chicago.
Cavallari was driving with a California license but Illinois law requires those living in the state for more than 90 days to get an Illinois license.
She took to Twitter to voice for her frustration and tweeted, "Who knew having a California driver's license in Illinois was a CRIME to be escorted to the police station to post bail?!!"
No details on how fast Cavallari was traveling have been released.
Cavallari is the wife of Chicago Bears quarterback Jay Cutler.
The Associated Press contributed to this report.
