The Ferengi /fəˈrɛŋɡi/ are a fictional extraterrestrial race from the Star Trek universe. They first appeared in "The Last Outpost", the fifth episode of Star Trek: The Next Generation in 1987, during which they made first contact with the United Federation of Planets in 2364 on the planet Delphi Ardu, though they had been mentioned in the series' pilot, "Encounter at Farpoint". They and their culture are characterized by a mercantile obsession with profit and trade, and their constant efforts to swindle unwary customers into unfair deals. They are also known for their business acumen and for rampant misogyny. They also sometimes force their women into the sex trade. Notable Ferengi characters include Quark, Rom, Nog, Ishka, Zek, and Brunt, all of whom were featured prominently in Star Trek: Deep Space Nine.

Their home planet, Ferenginar, is the center of the Ferengi Alliance and is governed by the Grand Nagus and a Commerce Authority made primarily of the Council of Economic Advisors (formerly Board of Liquidators). Like most of their culture, their religion is also based on the principles of capitalism: they offer prayers and monetary offerings to a "Blessed Exchequer" in hopes of entering the "Divine Treasury" upon death, and fear an afterlife spent in the "Vault of Eternal Destitution".