John Clements Wickham (21 November 17986 January 1864) was a Scottish explorer, naval officer, magistrate and administrator. He was first officer on during its second survey mission, 1831–1836, under captain Robert FitzRoy. The young naturalist and geologist Charles Darwin was a supernumerary on the ship, and his journal was published as "The Voyage of the Beagle". After that expedition, Wickham was promoted to Commander and made captain of the "Beagle" on its third voyage, from 1837 and conducted various maritime expeditions and hydrographic surveys along the Australian coastline.