Quoile Castle is a castle situated 1.5 miles (2.4km) from Downpatrick, County Down, Northern Ireland, just off the main road from Downpatrick to Strangford, on the east bank of the River Quoile. It is a 16th-century tower house, which was inhabited into the 18th century. Quoile Castle tower house is a State Care Historic Monument in the townland of Quoile, in Down District Council area, at grid ref: J4963 4701.