The Ross expedition was a voyage of scientific exploration of the Antarctic in 1839 to 1843, led by James Clark Ross, with two unusually strong warships, HMS Erebus and HMS Terror. It explored what is now called the Ross Sea and discovered the Ross Ice Shelf. On the expedition, Ross discovered the Transantarctic Mountains and the volcanoes Mount Erebus and Mount Terror, named after each ship. The young botanist Joseph Dalton Hooker made his name on the expedition.
The expedition confirmed the existence of the continent of Antarctica, inferred the position of the South Magnetic Pole and made substantial observations of the zoology and botany of the region, resulting in a monograph on the zoology and a series of four detailed monographs by Hooker on the botany, collectively called Flora Antarctica, published in parts between 1843 and 1859. Among the expedition's biological discoveries was the Ross seal, a species confined to the pack ice of Antarctica. The expedition was also the last major voyage of exploration made wholly under sail.