William Tierney Clark FRS FRAS (23 August 1783 – 22 September 1852) was an English civil engineer particularly associated with the design and construction of bridges. He was among the earliest designers of suspension bridges. Internationally, he is revered for his design of the Széchenyi Chain Bridge across the Danube in Budapest, Hungary, for which Marlow Bridge was a nearly identical, but smaller, prototype. The first bridge linking Buda and Pest, it was designed by Tierney Clark in 1839, with construction supervised locally by Scotsman Adam Clark (no relation). It opened in 1849.