The Barrow is a river in Ireland. It is one of The Three Sisters; the other two being the River Suir and the River Nore. The Barrow is the longest of the three rivers. At 192 km (120 mi), it is the second-longest river in Ireland, behind the River Shannon. The catchment area of the River Barrow is 3,067 km². The river's long term average flow rate is 37.4 cubic metres per second.