The Lam Brook is a stream in the West Country of England, which rises in a number of springs on the southern end of the Cotswold Hills and runs in a generally southerly direction for approximately 2.5 miles (4.0 km) before joining the river Avon at Lambridge in Bath. The brook is mentioned in an Anglo-Saxon charter of indeterminate date. There is evidence of watermills in the Swainswick valley but no working examples survive.