The River Beck is one of the tributaries of the River Ravensbourne

River Ravensbourne

The River Ravensbourne is a tributary of the River Thames in South London, England. It flows into the River Thames on the Tideway at Deptford, where its tidal reach is known as Deptford Creek.- Geography :...

 in south London.

The source of the River Beck is in Spring Park where Shirley

Shirley, London

Shirley is a place in the London Borough of Croydon, England. It is a suburban development situated 10 miles south south-east of Charing Cross.-Description:...

 and West Wickham

West Wickham

West Wickham is a place in the London Borough of Bromley, England. It is 10.3 miles south east of Charing Cross. West Wickham history dates back to early settlements existing since 1068, although the name `Wickham` is an indication of an earlier Anglo-Saxon settlement...

 meet. For its first mile or so it forms the border between the London boroughs of Croydon

London Borough of Croydon

The London Borough of Croydon is a London borough in South London, England and is part of Outer London. It covers an area of and is the largest London borough by population. It is the southernmost borough of London. At its centre is the historic town of Croydon from which the borough takes its name...

 and Bromley

London Borough of Bromley

The London Borough of Bromley is a London borough of south east London, England and forms part of Outer London. The principal town in the borough is Bromley.-Geography:...

. Indeed, historically, this was also the border between Surrey

Surrey

Surrey is a county in the South East of England and is one of the Home Counties. The county borders Greater London, Kent, East Sussex, West Sussex, Hampshire and Berkshire. The historic county town is Guildford. Surrey County Council sits at Kingston upon Thames, although this has been part of...

 and Kent

Kent

Kent is a county in southeast England, and is one of the home counties. It borders East Sussex, Surrey and Greater London and has a defined boundary with Essex in the middle of the Thames Estuary. The ceremonial county boundaries of Kent include the shire county of Kent and the unitary borough of...

. It gives its name to Beck Lane, Elmers End

Elmers End

Elmers End is a place in London Borough of Bromley, England. It has a large green space which is the centre of a gyratory. Very close to the combined railway station and Tramlink terminus bearing its name is the old sewage farm. The remains of this industrial site can still be seen...

 and Beck Way, Beckenham

Beckenham

Beckenham is a town in the London Borough of Bromley, England. It is located 8.4 miles south east of Charing Cross and 1.75 miles west of Bromley town...

.

The Beck flows into Cator Park, where it is joined by the Chaffinch Brook. The river after this juncture is called the Pool River, until it joins the River Ravensbourne

River Ravensbourne

The River Ravensbourne is a tributary of the River Thames in South London, England. It flows into the River Thames on the Tideway at Deptford, where its tidal reach is known as Deptford Creek.- Geography :...

 which in turn joins the River Thames

River Thames

The River Thames flows through southern England. It is the longest river entirely in England and the second longest in the United Kingdom. While it is best known because its lower reaches flow through central London, the river flows alongside several other towns and cities, including Oxford,...

.

The name probably derives from the town of Beckenham

Beckenham

Beckenham is a town in the London Borough of Bromley, England. It is located 8.4 miles south east of Charing Cross and 1.75 miles west of Bromley town...

 - Beohha's homestead (Old English). An alternative derivation may be the Middle English

Middle English

Middle English is the stage in the history of the English language during the High and Late Middle Ages, or roughly during the four centuries between the late 11th and the late 15th century....

 beck (stream), which would be an example of a tautological name. However this usage is not common in southern England.