Atwater is an unincorporated rural hamlet in Shaws Point Township, Macoupin County, Illinois, United States.

Atwater is 3.5 miles (5.6 km) east-southeast of Standard City.

There are several homes there, and a grainery, with no other businesses or services.

Atwater had a post office, which closed on October 12, 2002.

This Macoupin County, Illinois location article is a stub.