* River Thames - The Thames is the longest river in England and flows through London.
* River Severn - The Severn is the second longest river in England and flows through Wales and Gloucestershire.
* River Trent - The Trent is the third longest river in England and flows through the Midlands.
* River Ouse - The Ouse is the fourth longest river in England and flows through Yorkshire and Lincolnshire.
Wales
* River Wye - The Wye is the longest river in Wales and flows through the Brecon Beacons National Park.
* River Usk - The Usk is the second longest river in Wales and flows through the Black Mountains.
* River Taff - The Taff is the third longest river in Wales and flows through Cardiff and Merthyr Tydfil.
Scotland
* River Tay - The Tay is the longest river in Scotland and flows through Loch Tay and Perth.
* River Clyde - The Clyde is the second longest river in Scotland and flows through Glasgow.
* River Spey - The Spey is the third longest river in Scotland and flows through the Cairngorms National Park.
Northern Ireland
* River Bann - The Bann is the longest river in Northern Ireland and flows through Lough Neagh.
* River Foyle - The Foyle is the second longest river in Northern Ireland and flows through Derry.
* River Lagan - The Lagan is the third longest river in Northern Ireland and flows through Belfast.