A reservoir in West Lothian, Cobbinshaw lies to the west of the Pentland Hills. It was built c.1818 by James Jardine (1776 - 1858) to supply water to the Union Canal, which it still does under the management of British Waterways. Together with several lesser streams, the reservoir receives the Cobbinshaw Burn and Birk Burn, which rise on Cobbinshaw Moss, and the Benry Burn which forms on Benry Bog.
Today the Cobbinshaw provides popular recreational fishing and also forms a Site of Special Scientific Interest (SSSI) owing to its importance to wintering wildfowl.