The Challenger expedition was British expedition (1872–1876) in oceanographic research. The Challenger ship had a staff of six naturalists headed by Charles Wyville Thomson. It sailed nearly 128,000 kilometers (69,000 nautical miles) making studies of the life, water, and seabed in the three main oceans.

In 1872, the Royal Navy made HMS Challenger, a full-rigged, spar-decked corvette, available to the Royal Society for a three-and-a-half year oceanographic survey – the first of its kind. One of the most important scientific voyages ever made, the expedition laid the foundation for the modern science of oceanography. Two biologists, W. B. Carpenter and Wyville Thomson, persuaded the British government to equip the expedition to study deep-sea circulation and the distribution of life in the seas. The voyage set a pattern for similar oceanographic cruises during the late 19th and early 20th centuries. The voyage was the first to discover manganese nodules on the ocean floor, which were found at all sites in the ocean basins. The Challenger expedition also sampled the benthic fauna and flora down to depths of 4,500 fathoms (8,000 meters or 27,000 feet) thus demonstrating the existence of life in the abyssal depths. Hundreds of dredge samples were examined initially on board and the samples were preserved for analysis on return to England.