Flatrock Creek is a tributary of the Auglaize River in northeastern Indiana and northwestern Ohio in the United States. It drains a primarily rural farming area in the watershed of Lake Erie. It rises in a group of headwater streams along the border between Adams County, Indiana and Van Wert County, Ohio, approximately northeast of Decatur, Indiana. The creek flows northwest from Ohio into eastern Allen County, Indiana, then turns northeast at Monroeville, Indiana and flows into Paulding County, Ohio, past Payne and Paulding. It joins the Auglaize from the west approximately southwest of Defiance at . See also List of rivers of Indiana List of rivers of Ohio References Rivers of Indiana Rivers of Ohio Rivers of Paulding County, Ohio Rivers of Allen County, Indiana Tributaries of Lake Erie