The demonstration was staged by the Chicago Coalition for Justice in Palestine, according to a tweet posted by the U.S. Palestinian Community Network.
Grant Park is operated by the Chicago Park District, and permits are required to set up tents on the land.
Chicago police warned the protesters they were trespassing and may be arrested. No reports of any arrests were immediately known.
Police could be seen surrounding the protest around 4:45 p.m. The demonstration appeared to be cleared out with police removing all encampment tents by 5:05 p.m.
No further information about the protest was immediately available.