Opolis is a census-designated place (CDP) in Crawford County, Kansas, United States.

[2] Opolis was originally called Stateline (from the community's proximity to the Missouri state line), and under the latter name was laid out in 1868.

The post office was also called Stevenstown, Steventown, and Olopolis for some time in its early history.

[6] Opolis is located in the South Eastern corner of the state of Kansas close to the Missouri state line, approximately 133 miles (210 km) .due south of Kansas City, KS at latitude 37.344 and longitude -94.621.

It is in the Central time zone and observes Daylight Saving Time.,[7][8] The 2020 United States census counted 104 people, 47 households, and 34 families in Opolis.