Shown here are all the major rivers and tributaries of Ireland with their lengths (in kilometres and miles). Starting with the Northern Ireland rivers, and going in a clockwise direction, the rivers (and tributaries) are listed in regard to their entry into the different seas: the Irish Sea, the Celtic Sea and the Atlantic Ocean. Also shown are two tables. Table 1 shows the longest rivers in Ireland with their lengths (in kilometres and miles), the counties they flow through, and their catchment areas (in square kilometres). Table 2 shows the largest rivers in Ireland (by mean flow) in cubic metres per second.
The longest river in Ireland is the River Shannon, at 360.5 kilometres (224.0 mi). The river develops into three lakes along its course, Lough Allen, Lough Ree and Lough Derg. Of these, Lough Derg is the largest. The Shannon enters the Atlantic Ocean at the Shannon Estuary. Other major rivers include the River Liffey, River Lee, River Swilly, River Foyle, River Lagan, River Erne, River Blackwater, River Nore, River Suir, River Barrow (The Three Sisters), River Bann, River Slaney, River Boyne, River Moy and River Corrib.
Lengths obtained from the Ordnance Survey of Ireland: Rivers and their Catchment Basins 1958 (Table of Reference), and for the rivers Bann and Erne - Notes on River Basins by Robert A. Williams
TABLE 1
a
The length of the River Shannon from the Shannon Pot to Limerick City is 258 kilometres (160 mi) with a basin area of 11,700 km2.
The River Shannon's overall length (to Loop Head), using the Owenmore River (Glangevlin) as source, is 372 kilometres (231 mi), 11 km (7 mi) longer than the Shannon Pot source.
The River Shannon's overall length (to Loop Head), using the Boyle River's furthest source, is 392.1 kilometres (243.6 mi), making the Boyle-Shannon river the longest natural stream flow (source to sea) in Ireland, 31.6 km (19.5 mi) longer than the Shannon Pot source.
The River Shannon is a traditional freshwater river for just about 45% of its total length. Excluding the 102.2-kilometre (63.5 mi) tidal estuary from its total length of 360 kilometres (224 mi), if one also excludes the lakes (L. Derg 39 kilometres (24 mi), L. Ree 29 kilometres (18 mi), L. Allen 11 kilometres (7 mi) plus L. Boderg, L. Bofin, L. Forbes, L. Corry) from the Shannon's freshwater flow of 258.3 kilometres (160.5 mi), the Shannon as a freshwater river is only about 160 kilometres (100 mi) long.
b
The total basin area of the Three Sisters (Barrow, Nore and Suir) is 9,207 km2.
c
The traditional length given for the River Bann is 80 miles (129 km) which is the combined total length of Upper and Lower Bann rivers and doesn't include Lough Neagh.
The total length of the Ulster Blackwater from its source to the sea via L. Neagh and the Lower Bann is 186.3 km (115.75 mi), surpassed, in Ireland, only by the Shannon and Barrow rivers. This is the longest stream flow (source to sea) in Ulster.
d
The total basin area of the 6 km River Corrib is 3,138 km2
The total length of the River Robe's journey from its source near Ballyhaunis to Galway Bay (via Lough Mask, Cong canal and river, Lough Corrib and River Corrib) is 72 miles (116 km). This is the longest stream flow (source to sea) within the Corrib Basin.
Rivers in Northern Ireland
With length in miles (and km)
River Crana 12 miles (19 km)
River Lennon (Leannan) 28.5 miles (45.9 km)
River Foyle 80 miles (130 km) (total) — that portion named "Foyle" forms the border between the Republic of Ireland and Northern Ireland
River Deele 25.5 miles (41.0 km)
River Finn (County Donegal) — rises and flows mainly through County Donegal, Republic of Ireland 39.25 miles (63.17 km)River Reelan 10.5 miles (16.9 km)
River Mourne
River Derg 28 miles (45 km)
Mournebeg River 17.25 miles (27.76 km)
Owenkillew River 30 miles (48 km)
Glenelly River 22 miles (35 km)
Owenreagh River 14 miles (23 km)
River Strule 14.25 miles (22.93 km)Camowen River 28 miles (45 km)
Drumragh River 20.5 miles (33.0 km)
Fairy Water 17.75 miles (28.57 km)
Drumquin River 9.5 miles (15.3 km)
Routing Burn 13 miles (21 km)
Owenreagh River 16.5 miles (26.6 km)
Cloghfin River 14 miles (23 km)
River Faughan 29.5 miles (47.5 km)
River Roe 34.25 miles (55.12 km)
River Bann 90 miles (140 km)River Blackwater 56.7 miles (91.2 km)River Callan 26.5 miles (42.6 km)
Oona Water 17.75 miles (28.57 km)
River Torrent 25 miles (40 km)
River Tall 22.5 miles (36.2 km)
River Blackwater (Northern) 35.5 miles (57.1 km)
River Main 34 miles (55 km)
Six Mile Water 21 miles (34 km)
Ballinderry River 29 miles (47 km)
Moyola River 31 miles (50 km)
Cusher River 25 miles (40 km)
River Dun
River Bush 33.5 miles (53.9 km)
River Erne 80 miles (130 km) (See Atlantic rivers)
River Lagan 53.5 miles (86.1 km)River Farset
River Quoile 27.5 miles (44.3 km)
Clanrye (Newry) River 27 miles (43 km)
Rivers in the Republic of Ireland, flowing into the Irish Sea
With length in miles (and km)
Castletown River 28 miles (45 km)Cully Water 14.5 miles (23.3 km)
Kilcurry River 11.5 miles (18.5 km)
River Fane 38.25 miles (61.56 km)
River Glyde 34.75 miles (55.92 km)
River Dee, County Louth 37.75 miles (60.75 km)
River Boyne 70 miles (110 km)River Owenroe (Moynalty) 23.5 miles (37.8 km)
River Blackwater, Kildare and Meath 20 miles (32 km)
River Blackwater, Cavan and Meath 42.5 miles (68.4 km)
Moynalty River 23.5 miles (37.8 km)
Athboy River 22.5 miles (36.2 km)
Stonestown River 20 miles (32 km)
Dale River 22.5 miles (36.2 km)
Kinnegad River 19.5 miles (31.4 km)
Yellow River 16 miles (26 km)
River Tolka 20.75 miles (33.39 km)
River Liffey 82 miles (132 km)Kings River 16.5 miles (26.6 km)
Morell River 7 miles (11 km)
River Rye 15.5 miles (24.9 km)Lyreen River
River Camac
River Poddle
River Dodder 17 miles (27 km)Owendoher River
River Dargle 12.5 miles (20.1 km)
River Vartry 20.5 miles (33.0 km)
River Avoca (Ovoca) 9.5 miles (15.3 km)River Avonmore 22.75 miles (36.61 km)
River Avonbeg 16.5 miles (26.6 km)
Aughrim River 5.75 miles (9.25 km)
River Slaney 73 miles (117 km)Derreen River 25 miles (40 km)
River Derry 21 miles (34 km)
River Bann (Wexford) 26 miles (42 km)
Rivers in the Republic of Ireland, flowing into the Celtic Sea
With length in miles (and km)
River Barrow 119.5 miles (192.3 km)
Philipstown River 15.75 miles (25.35 km)
Figile River 20.75 miles (33.39 km)
River Slate 17 miles (27 km)
River Triogue 16.75 miles (26.96 km)
Finnery River
Tully Stream 8 miles (13 km)
River Greese 22 miles (35 km)
Burren River 24 miles (39 km)
River Nore 87.75 miles (141.22 km)River Erkina 22.5 miles (36.2 km)River Goul 23.25 miles (37.42 km)
River Dinan 24.75 miles (39.83 km)
Kings River 28.75 miles (46.27 km)
River Suir 114.75 miles (184.67 km)River Drish 19.75 miles (31.78 km)
River Clodiagh 20.5 miles (33.0 km)
Aherlow River 27 miles (43 km)
River Ara 18.25 miles (29.37 km)
River Anner 23.5 miles (37.8 km)
John's River
River Tar 18.75 miles (30.18 km)River Duag
River Colligan 15 miles (24 km)
River Mahon 15.75 miles (25.35 km)
River Blackwater, Cork 104.5 miles (168.2 km)River Owentaraglen 17.25 miles (27.76 km)
River Allow 22.75 miles (36.61 km)
River Funshion 34.75 miles (55.92 km)
River Finisk 17.5 miles (28.2 km)
River Awbeg 31.75 miles (51.10 km)
River Dalua 15.5 miles (24.9 km)
River Bride 40 miles (64 km)
River Womanagh 19 miles (31 km)
Owenacurra River 13.25 miles (21.32 km)
Glashaboy River 15 miles (24 km)
River Lee 55.5 miles (89.3 km)River Sullane 22.5 miles (36.2 km)
Shournagh River 17 miles (27 km)
River Bride 21 miles (34 km)
River Bandon 45 miles (72 km)
River Ilen 20.75 miles (33.39 km)
Argideen River 17.75 miles (28.57 km)
River Owenabue 20.5 miles (33.0 km)
Rivers in the Republic of Ireland, flowing into the Atlantic Ocean
With length in miles (and km)
Roughty River 16.75 miles (26.96 km) (flowing into Kenmare Bay) at Kenmare
River Laune 14 miles (23 km)River Flesk 28.25 miles (45.46 km)
Gweestin River 13.75 miles (22.13 km)
Caragh River 14 miles (23 km)
River Inny (Kerry) 16.5 miles (26.6 km)
Cummeragh River 9.5 miles (15.3 km)
River Ferta
River Carrowbeg
River Maine 26.5 miles (42.6 km)Brown Flesk 19.75 miles (31.78 km)
River Feale 46 miles (74 km)River Galey 27 miles (43 km)
Allaghaun River 13.75 miles (22.13 km)
Smerlagh (Smaorlagh) River 15.5 miles (24.9 km)
Shanow River 15.25 miles (24.54 km)
River Shannon 224 miles (360 km)Owenmore River (County Cavan) 9 miles (14 km)
Arigna River 14 miles (23 km)
Feorish River 19.5 miles (31.4 km)
River Brosna 49.25 miles (79.26 km)Clodiagh River 24.25 miles (39.03 km)
Tullamore River 12.5 miles (20.1 km)
Silver River 24 miles (39 km)
Bunowen River 16 miles (26 km)
Little Brosna River 36 miles (58 km)River Camcor 16.25 miles (26.15 km)
Ballyfinboy River 20.75 miles (33.39 km)
Nenagh River 28.5 miles (45.9 km)Ollatrim River 18.5 miles (29.8 km)
River Inny 55.5 miles (89.3 km)River Tang 15.5 miles (24.9 km)
River Suck 82.5 miles (132.8 km)River Shiven 21.25 miles (34.20 km)
Boyle River (Total) 40 miles (64 km)
Boyle River 13.75 miles (22.13 km)Lung River 17.75 miles (28.57 km)
Breedoge River 11.75 miles (18.91 km)
Camlin River 27 miles (43 km)
Mulkear River 15.25 miles (24.54 km)Bilboa River 19.5 miles (31.4 km)
River Deel 39.5 miles (63.6 km)
River Maigue 38.75 miles (62.36 km)
River Fergus 36.5 miles (58.7 km)
River Corrib 5.75 miles (9.25 km)Cregg River (via Lough Corrib)
River Clare (via Lough Corrib) 57.75 miles (92.94 km)Grange River 17 miles (27 km)
Abbert River 25.25 miles (40.64 km)
River Black 17.75 miles (28.57 km)
Aille River (Connacht) 18.5 miles (29.8 km)
Baelanabrack River 11 miles (18 km)
River Robe (via Loughs Mask and Corrib) 39.25 miles (63.17 km)
River Clarin 19.75 miles (31.78 km)
Kilcolgan River 9.5 miles (15.3 km)Dooyertha River 23.75 miles (38.22 km)
Kinvarra River
River Doonbeg 25.75 miles (41.44 km)
River Inagh 22.75 miles (36.61 km)
Carrowbeg River 10 miles (16 km)
Bunowen River 13.25 miles (21.32 km)
River Erriff 20.5 miles (33.0 km)
Owenglin River 11.5 miles (18.5 km)
Ballynahinch River 18.5 miles (29.8 km)
Cashla River 13.25 miles (21.32 km)
Owenboliska River 13.25 miles (21.32 km)
Glenamoy River 13.75 miles (22.13 km)
Cloonaghmore River 19.75 miles (31.78 km)
Owenmore River (County Mayo) (incl. Carrowmore Lake) 29.25 miles (47.07 km)
Owenduff River 17.75 miles (28.57 km)
Newport River 18.25 miles (29.37 km)
River Moy 62.5 miles (100.6 km)Deel River 28 miles (45 km)
Manulla River 19 miles (31 km)
Gweestion River 23 miles (37 km)
Owengarve River 16 miles (26 km)
River Glore 17 miles (27 km)
Easky River, County Sligo 18.5 miles (29.8 km)
Ballisodare River 5.5 miles (8.9 km)Owenmore River (County Sligo) 32.5 miles (52.3 km)
Owenbeg River 14.75 miles (23.74 km)
Unshin River 14.25 miles (22.93 km)
River Garavogue (including L. Gill and R. Bonnet) 31.5 miles (50.7 km)
River Erne 80 miles (130 km) — mainly formed by Upper and Lower Lough Erne in County Fermanagh, Northern Ireland
River Annalee 41.75 miles (67.19 km)
River Cladagh (including Arney) 22 miles (35 km)
Sillees River 33 miles (53 km)
River Ballinamallard 16 miles (26 km)
River Swanlinbar 18 miles (29 km)
River Woodford 18.5 miles (29.8 km)
Dromore River 23.25 miles (37.42 km)
Yellow River 17.25 miles (27.76 km)
Colebrooke River 35 miles (56 km)
River Finn (Erne tributary) 31.5 miles (50.7 km)
Owenea River 16.25 miles (26.15 km)
Oily River 13 miles (21 km)
Bungosteen River 15.5 miles (24.9 km)
Ballintra River 14 miles (23 km)
River Eske 15.25 miles (24.54 km)
River Gweebarra 19.75 miles (31.78 km)
River Swilly 25.5 miles (41.0 km)
TABLE 2
a The River Shannon's 209 m3/s is to Limerick City (Catchment area: 11,700 km2). If the discharges from all of the rivers and streams into the Shannon Estuary (including the rivers Feale 34.6m3/s, Maigue 15.6m3/s, Fergus 25.7m3/s, and Deel 7.4m3/s) are added to the discharge at Limerick giving a total catchment of 16,865 km2, the total discharge of the River Shannon at its mouth at Loop Head reaches 300 m3/s
b The River Bann's 92 m3/s is to Movanagher Gauging station (Basin area 5209.8 km2). The 102.5 m3/s is based on the total basin area of 5808 km2 .
c The Three Sisters (Barrow, Nore & Suir) total flow into Waterford Harbour is 154 m3/s and the combined flow of the Barrow and Nore rivers is 86 m3/s before joining the river Suir near Waterford City.
