King John's Castle may refer to: King John's Castle (Limerick), Limerick City, Ireland King John's Castle (Carlingford), County Louth, Ireland King John's Castle (Kilmallock), County Limerick, Ireland King John's Castle in Kineton, Warwickshire, United Kingdom King John's Castle, a horse that finished second in the 2008 Grand National
See also Athenry, County Galway Naas, County Kildare Odiham Castle near Odiham, Hampshire Trim Castle, County Meath