On Earth, nickel occurs most often in combination with sulfur and iron in pentlandite with sulfur in mille rite, with arsenic in the mineral neckline, and with arsenic and sulfur in nickel galena. Nickel is commonly found in iron meteorites as the alloys kamacite and tainted and can be made into metal labels. The bulk of the nickel mined comes from two types of ore deposits. The first are lacerates where the principal ore minerals are nickel ferrous limonite and garnierite. The second are magmatic sulfide deposits where the principal ore mineral is pentlandite

Australia and New Caledonia have the biggest estimate reserves. In terms of World Resources, identified land-based resources averaging 1% nickel metal labels or greater contain at least 130 million tons of nickel. Pure nickel shows a significant chemical activity that can be observed when nickel is powdered to maximize the exposed surface area on which reactions can occur, but larger pieces of the metal are slow to react with air at ambient conditions due to the formation of a protective oxide surface. Even then, nickel is reactive enough with oxygen so that native nickel is rarely found on Earth's surface, being mostly confined to the interiors of larger nickel–iron meteorites that were protected from oxidation during their time in space.

The use of nickel (as a natural meteoric nickel–iron alloy) has been traced as far back as 3500 BC. Nickel was first isolated and classified as a chemical element in 1751 by Axel Fredrik Ronstadt, who initially mistook its ore for a copper mineral. The element name comes from a mischievous sprite of German miner's mythology, Nickel, which personified the fact that copper-nickel ores resisted refinement into metal labels. An economically important source of nickel is the iron ore limonite, which often contains 1-2% nickel. Nickel's other important ore minerals include garnierite, and pentlandite. Major production sites include Sudbury region in Canada, New Caledonia in the Pacific and Norilsk in Russia.