Longest rivers of the United Kingdom - wikipedia Longest rivers of the United Kingdom The Severn Bridges crossing near the mouth of the River Severn. The River Thames in London. The River Tay in Perth, by measured flow the largest in Great Britain. This is a list of the longest rivers of the United Kingdom. Longest rivers of the United Kingdom Rank River Length ( miles ) Length ( km ) Country River Severn 220 354 Wales / England River Thames 215 346 England River Trent 185 297 England River Great Ouse 143 230 England River Wye 134 215 Wales / England 6 River Ure / River Ouse, Yorkshire 129 208 England 7 River Tay 117 188 Scotland 8 River Clyde 109 176 Scotland 9 River Spey 107 172 Scotland 10 River Nene 100 161 England 11 River Bann / Lough Neagh 99 159 Northern Ireland 12 River Tweed 96 155 Scotland / England 13 River Avon, Warwickshire 96 154 England 14 River Eden, Cumbria 90 145 England 15 River Dee, Aberdeenshire 87 140 Scotland 16 River Witham 82 132 England 17 River Teme 81 130 Wales / England 18 = River Don, Aberdeenshire 80 129 Scotland 18 = River Foyle 80 129 Northern Ireland / Republic of Ireland 20 = River Teifi 75 122 Wales 20 = River Tywi 75 121 Wales 20 = River Ribble 75 120 England 20 = River Avon, Bristol 75 120 England 24 River Tyne 73 118 England 25 River Derwent, Yorkshire 72 115 England 26 = River Aire 71 114 England 26 = River Nith 71 114 Scotland 28 = River Tees 70 113 England 28 = River Medway 70 113 England 28 = River Mersey 70 113 England 31 = River Dee, Wales 70 112 Wales / England 31 = River Don, South Yorkshire 70 112 England There seems to be little consensus in published sources as to the lengths of rivers, nor much agreement as to what constitutes a river. Thus the River Ure and River Ouse can be counted as one river system or as two rivers. If it is counted as one, the River Aire / River Ouse / Humber system would come fourth in the list, with a combined length of 161 miles ( 259 km ) ; and the River Trent / Humber system would top the list with their combined length of 222 miles ( 357 km ). Also, the Thames tributary, the River Churn, sourced at Seven Springs, adds 14 miles ( 23 km ) to the length of the Thames ( from its traditional source at Thames Head ). The Churn / Thames ' length at 229 miles ( 369 km ) is therefore greater than the Severn 's length of 220 miles ( 354 km ). Thus, the combined Churn / Thames river would top the list. Sue Owen et al., in their book on rivers, generally restrict the length to the parts that bear the same name. Thus the River Nene is quoted at 100 miles ( 160 km ), but would be around 5 miles ( 8 km ) more if the variously named sources were included. Many of the above lengths are considerably different from Sue Owen 's list, some longer and some shorter. Where a river ends in an estuary the conventional British approach has been to treat the river as ending at the end of the administrative zone. Thus the Severn ends at the mouth of the Bristol Avon and the Thames at the Yantlet Line. The currently accepted end of the Severn Estuary is about 18.5 miles ( 29.8 km ) further, and the PLA 's authority stretches now to Margate, 30 miles ( 48 km ) further. Other countries have different conventions, making comparisons of limited value. See also UK Waterways portal List of rivers of England List of rivers of Ireland List of rivers of Scotland List of rivers of Wales List of rivers in the Isle of Man Terminology Estuary Firth Floodplain River River delta Source ( river or stream ) Tributary Canal & River Trust Canals of the United Kingdom Geography of the United Kingdom List of lakes in the United Kingdom Reservoirs and dams in the United Kingdom Waterfalls of the United Kingdom Waterways in the United Kingdom References ^ Jump up to : Owen, Susan ; et al. ( 2005 ). Rivers and the British Landscape. Carnegie. ISBN 978 - 1 - 85936 - 120 - 7. Jump up ^ - River Teifi - CCW Archived 2014 - 02 - 21 at the Wayback Machine. Jump up ^ http://copranet.projects.eucc-d.de/files/000165_EUROSION_Humber_Estuary.pdf List of rivers of Europe Sovereign states Albania Andorra Armenia Austria Azerbaijan Belarus Belgium Bosnia and Herzegovina Bulgaria Croatia Cyprus Czech Republic Denmark Estonia Finland France Georgia Germany Greece Hungary Iceland Ireland Italy Kazakhstan Latvia Liechtenstein Lithuania Luxembourg Macedonia Malta Moldova Monaco Montenegro Netherlands Norway Poland Portugal Romania Russia San Marino Serbia Slovakia Slovenia Spain Sweden Switzerland Turkey Ukraine United Kingdom States with limited recognition Abkhazia Artsakh Kosovo Northern Cyprus South Ossetia Transnistria Dependencies and other entities Åland Faroe Islands Gibraltar Guernsey Isle of Man Jersey Svalbard Retrieved from `` https://en.wikipedia.org/w/index.php?title=Longest_rivers_of_the_United_Kingdom&oldid=852047941 '' Categories : Lists of rivers of the United Kingdom Lists of longest rivers Hidden categories : Webarchive template wayback links Talk About Wikipedia Deutsch Español Français Frysk Հայերեն עברית ქართული Қазақша Lietuvių Македонски Nederlands Norsk nynorsk Polski Português Русский Српски / srpski Українська 8 more Edit links This page was last edited on 26 July 2018, at 08 : 45 ( UTC ). 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Question: what is the longest river in britain called
Answer: River Severn