Milton is a home rule-class city along the south bank of the Ohio River in Trimble County, Kentucky, United States. The population was 597 at …Milton is a home rule-class city along the south bank of the Ohio River in Trimble County, Kentucky, United States. The population was 597 at the time of the 2020 census, making it the largest city in Trimble County. The Milton-Madison Bridge connects it to Madison, Indiana, and is the only road link between the two states for 40 miles in either direction.