Palmyra is a city in Marion County, Missouri, and serves as the county seat. Located in the north-central region of the state, it is part of the Hannibal Micropolitan Statistical Area, which centers on the nearby city of Hannibal.
According to the 2020 census, Palmyra had a population of 3,613 residents. As the county seat, the city functions as the administrative center for Marion County government and its operations.