All nonresidents of Cincinnati engaged in business within the City of Cincinnati, or whose compensation was earned within Cincinnati and did not have Cincinnati tax withheld from their earnings, must file a tax return whether or not tax is due.
So if you are an employee receiving a W-2, then your employer should be withholding Cincinnati income tax and remitting it on your behalf.
Depending on where you live in KY, you may also have a local tax and most likely will receive a credit to avoid the double local tax on wages.
See the attached from the Cinti Department of Revenue:
https://www.cincinnati-oh.gov/finance/income-taxes/
*A reminder that posts in a forum such as this do not constitute tax advice.
Also keep in mind the date of replies, as tax law changes.
