John Joseph Merlin (born Jean-Joseph Merlin, 6 September 1735 – 8 May 1803) was a Belgian from the Prince-Bishopric of Liège in the Holy Roman Empire. He was a Freemason, clock-maker, musical-instrument maker, and inventor. He moved to England in 1760. By 1766 he was working with James Cox and creating automatons such as Cox's timepiece and the Silver Swan. By 1773 he was designing and making innovative keyboard instruments. In 1783 he opened Merlin's Mechanical Museum in Princes Street, Hanover Square, London, a meeting-place for the gentry and nobility.In addition to his clocks, musical instruments and automata, Merlin is credited with the invention of inline skates in the 1760s. He was referred to by contemporaries as "The Ingenious Mechanic". He was friendly with composer Joseph Haydn.