It is sometimes claimed that the name "Hallen" is from the Welsh for salt, 'halen', or from an Anglo-Saxon word of the same meaning, however, 16th century spellings (e.g. Hallyende) make it clear that this is not the case; the name is apparently Middle or Early Modern English from 'hall' (hall) or 'hale' (nook, corner, stretch of alluvial land) + 'ende' (end).

A large underground petroleum storage facility was built into the hillside behind the village during World War II, to provide protection from German bombing.

In the 19th and early 20th centuries, Hallen was a popular stop off point for travellers making their way from the South West to the Aust Ferry, which would cross the River Severn to Wales.

The brewery structure is still visible today attached to the last remaining pub, The King William IV.

The village retains some old world charm in places (War Memorial and Oakhill Lane cottages), but has been bisected by the M5 motorway which has left it somewhat desolate.