Measuring the length of rivers is always tricky and open to debate. Due to difficulties in determining exactly where one river stops and another begins, and deciding where a river ends and an estuary begins, not all longest river lists will be identical.
That said, most people would agree that Scotland’s longest river is the River Tay.
The Top 10 Longest Rivers in Scotland
(1) River Tay – 188 km (117 miles)
Rising in Ben Lui (Argyll and Bute) and flowing into the North Sea at the Firth of Tay, the River Tay is Scotland’s longest river and the seventh-longest river in Great Britain. It is also the largest river in the British Isles in terms of discharge.
Learn more about the River Tay.
(2) River Spey – 172 km (107 miles)
The River Spey rises in Loch Spey in the Scottish Highlands and flows into the Moray Firth at Spey Bay. It is the UK’s eighth-longest river, and it is Scotland’s fastest flowing river.
Learn more about the River Spey.
(3) River Clyde – 170 km (106 miles)
Rising in the Lowther Hills in South Lanarkshire, the River Clyde flows into the Firth of Clyde at Inverclyde in Argyll. The River Clyde runs through the city of Glasgow.
Learn more about the River Clyde.
(4) River Tweed – 156 km (97 miles)
The River Tweed flows along the border of Scotland and northern England. It rises at Tweed’s Well in Tweedsmuir, and it flows into the North Sea at Berwick-upon-Tweed.
Learn more about the River Tweed.
(5) River Dee – 140 km (87 miles)
Located in Aberdeenshire, the River Dee rises in the Wells of Dee (Cairngorms), and flows into the North Sea at Aberdeen.
Learn more about the River Dee.
(6) River Don – 131 km (81 miles)
The River Don rises in the Grampian Mountains at Ladder Hills, and it flows into the North Sea at Aberdeen at the Bridge of Don.
Learn more about the River Don.
(7) River Nith – 114 km (71 miles)
The River Nith’s source is located at Enoch Hill in the Carsphairn Hills (East Ayrshire), and it flows into the Solway Firth.
Learn more about the River Nith.
(8) River Teith – 113 km (70 miles)
The River Neith is formed in Callander (Stirlingshire) at the point where the River Leny and the Eas Gobhain join. It flows into the River Forth to the north-west of Stirling.
(9) River Findhorn – 100 km (62 miles)
Located in the north-east Scotland, the River Findhorn flows into the Moray Firth.
(10) River Deveron – 97 km (60miles)
The source of the River Deveron is in the Grampian Mountains at Ladder Hills. It flows into the Moray Firth at a point between the towns of Banff and Macduff.
The River Forth sometimes appears on lists of Scotland’s longest rivers. Officially, the river measures 47 km (29 miles), but some people add the length of the Firth of Forth to the River Forth’s length.