Anthony James "Tony" Naldrett, FRSC (1933 – 21 June 2020) was an English and Canadian geologist.
He was an authority on the geology and origin of nickel-copper-platinum group element deposits, the tectonic setting in which they occur, the petrology of associated rocks, and controls on their composition.
Later that year he moved to Canada, where he worked in Sudbury as a geologist for Falconbridge Nickel Mines.
Naldrett authored or co-authored 254 refereed publications, plus wrote or edited eight books covering his research in geology, mineralogy and chemistry of magmatic sulfide deposits and related rocks.
His research covered most of the world's magmatic sulfide ores, including those at Sudbury, the Abitibi Belt, Voisey's Bay, the West Australian Widgiemooltha Komatiite deposits, the Zimbabwe Nickel deposits, deposits of the Raglan and Thompson belts, Norilsk, Pechenga, Jinchuan, the Duluth Complex, the Bushveld and Stillwater complexes, Zimbabwe's Great Dyke, and at the Lac des Îles igneous complex of northwestern Ontario.