Don LaFontaine was an American voice actor.

LaFontaine recorded an estimated 5,000 movie trailers over three decades, including Dr. Strangelove, The Elephant Man, The Terminator, and Batman Returns. Many of these trailers began with the phrase "In a world...." In a 2007 interview, LaFontaine explained the strategy behind his signature catchphrase: "We have to very rapidly establish the world we are transporting them to. That's very easily done by saying, 'In a world...' You very rapidly set the scene."

He also lent his voice to numerous television commercials, including spots for Chevrolet, Pontiac, Ford, Budweiser, McDonald's, Coca-Cola and Geico, among many others. In addition, LaFontaine did voiceover work for many television shows and network promotional campaigns. These included the magazine series Entertainment Tonight and The Insider, as well as ABC, CBS, Fox, NBC, UPN, TNT, TBS and Cartoon Network.

A native of Duluth, Minnesota, LaFontaine enlisted in the Army in 1958, where he worked as a recording engineer. After his discharge, he moved to New York to work in the promo industry in the early 1960s. As an audio engineer, he produced radio spots for movies with producer Floyd Peterson. When an actor failed to show up for a recording session, LaFontaine filled in, recording radio ads for the 1964 Western, Gunfighters of Casa Grande. The client, MGM, liked his performance, and LaFontaine began his voiceover career.

In a rare onscreen appearance in 2006, he parodied himself in a television commercial for Geico car insurance.

LaFontaine died September 1, 2008, in Los Angeles, California. He was 68.