Smedley's Hydro was a hydrotherapy complex in Matlock, Derbyshire. A Grade II listed building, it is now used as the headquarters of the Derbyshire County Council.
Matlock had developed as a spa town after thermal springs were discovered, and Smedley's Hydro was built on Matlock Bank by John Smedley in 1853, becoming the largest hydro in the town:
John Smedley was not the first to recognise and exploit the effects of water treatment on various illnesses, but it was Smedley whose conviction and enterprise established Hydrotherapy firmly in Matlock, and for a century made it one of the most celebrated centres of the "water cure". By the outbreak of war in 1939, Smedley's Hydro was world famous, its guests having included Robert Louis Stevenson, Sir Thomas Beecham, Ivor Novello, Jimmy Wilde, and Gilbert Jessop, to name but a few.