Rochester is a city in Butler County, Kentucky, United States, at the confluence of the Green and Mud Rivers. The population was 186 at the 2000 census. It is named for Rochester, New York. This Rochester is the smallest municipality by population in the United States by that name.
Rochester is located at 37°12′39″N 86°53′33″W / 37.21083°N 86.8925°W / 37.21083; -86.8925 (37.210712, -86.892483).
According to the United States Census Bureau, the city has a total area of 0.4 square miles (1.2 km²), of which, 0.4 square miles (1.1 km²) of it is land and 2.22% is water.