- Sidney is a city located in Shelby County, Ohio, United States. It is the county seat of Shelby County and has a population of around 20,000 people. The city is known for its historic architecture, including the Historic Sidney Theatre and the Shelby County Courthouse. Sidney offers various recreational activities, such as hiking, fishing, and boating at nearby Lake Loramie State Park. The city also hosts regular events and festivals, including the Shelby County Fair and the Country Concert at Hickory Hills Lake. Sidney is home to several industries and offers a range of employment opportunities.