Major rivers of the United Kingdom

This is a list of the major rivers of the United Kingdom, as being prominent in length, flow volume (discharge rate), or both.

Sue Owen et al., in their book on rivers, generally restrict the length to the parts that bear the same name.

Many of the above lengths are considerably different from Sue Owen's list, some longer and some shorter.

Thus the Severn ends at the mouth of the Bristol Avon and the Thames at the Yantlet Line.

The calculation of mean flow presents its own challenges, relying on sampling at a limited number of gauging stations.

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