Portora Castle is a castle in Enniskillen, County Fermanagh, Northern Ireland. The castle was built for Sir William Cole who purchased the land in 1612. It is strategically positioned by the narrow exit of the River Erne into the Lower Lough Erne. It is a State Care Historic Monument sited in the townland of Portora, in Fermanagh District Council area, at grid ref: H2221 4531.