Avon Water[a] is a small river draining some of the southwest of the New Forest in Hampshire to The Solent.

West of the upper part of its archetypally dendritic drainage basin, which has formed due to the forest's heath soil, is the due south, much larger River Avon, rising in Wiltshire.

It is the smallest of three rivers (properly so called) which drain all but the north, west and east edges of the New Forest.

[3] It flows into the Solent at Keyhaven,[4] close to the shingle bank that leads to Hurst Castle.

It is labelled on Thomas Milne's map of Hampshire published by William Faden in 1791.