The 2021 Chicago Challenger was a professional tennis tournament played on outdoor hard courts.

It was part of the 2021 WTA 125K series.

It was the second edition of the tournament which took place from August 16 to 22, 2021 in Chicago, United States.

[1] The following players received wildcards into the singles main draw: The following players received entry using protected rankings: The following players received entry from the qualifying draw: The following pair received a wildcard into the doubles main draw: The following pairs received entry into the doubles main draw using protected rankings: