Trail City is an unincorporated community straddling Dewey County, South Dakota and Corson County, South Dakota, United States.

Although not tracked by the Census Bureau, Trail City has been assigned the ZIP code of 57657.

Due to confusion in the mails with two other South Dakota post offices (Cheyenne Agency and Cheyenne Falls), alternate town names were considered.

The community was named for a cattle drive trail near the original town site according to some secondary sources.

This South Dakota state location article is a stub.