Wilhelm Winternitz (March 1, 1835), Josefov (Jaromer) Josefstadt (now a part of Jaromer, Okres Náchod), Bohemia – February 22, 1917, Vienna) was a Czech-Austrian Jewish physician and hydropathist.
He was an influential neurologist and hydropathist who at the time was commonly characterized as "the father of scientific hydrotherapy".