Donald LaFontaine was an American voice actor famous for recording over 5,000 movie trailers and (according to his website) over 350,000 television commercials, network promotions, and video game trailers. His signature voice was perceived as being both ominous and sonorous. His nicknames included "Thunder Throat" and "The Voice of God". He became identified with the phrase "in a world...", which has been used in movie trailers so frequently that it has become a cliché. He also parodied this cliché several times, most recently in a commercial for GEICO insurance.

LaFontaine was born August 26, 1940 in Duluth, Minnesota to Alfred and Ruby LaFontaine. He began his career as a recording engineer at the National Recording Studios, where he had the opportunity to work with Floyd Peterson producing promo spots for Dr. Strangelove. Peterson incorporated many of LaFontaine’s ideas for the spots, and not long after, they went into business together. While working on the 1964 western Gunfighters of Casa Grande, LaFontaine had to fill in for an unavailable voice actor to finish a client’s presentation. Not long after, the client bought the spots, and LaFontaine’s career as a voice actor had been sealed. Prior and into the 1970s, LaFontaine developed his signature style of a strong narrative approach, and heavy melodramatic coloration of his voice work.

LaFontaine’s signature voice commanded a busy schedule. He is said to have voiced about 60 promotions a week, and sometimes as many as 35 in a single day. It has been said that his voice-over added prestige and excitement to what might otherwise have been a "snoozer" movie. Most studios were willing to pay a high fee for his service, thanks in no small part to his rigorous efforts and golden voice. His income was reportedly in the millions.

In a 2007 interview, LaFontaine explained the strategy behind his signature catch phrase, "in a world where...":

"We have to very rapidly establish the world we are transporting them to. That's very easily done by saying, `In a world where ... violence rules.' `In a world where ... men are slaves and women are the conquerors.' You very rapidly set the scene."

Famous for being driven to voice-over jobs in a personalized limo with a full time driver, so as not to waste time parking and going from job to job, he began recording many promotions from his own palatial estate in the Hollywood Hills, saving the time from traveling to many high-profile recording studios. This was due to the advent of ISDN technology that allows voice-actors to communicate with high clarity in real time to studios around the world, and to the Internet where a file can be recorded and e-mailed to a studio within seconds.

Similar voice actors Ashton Smith, Hal Douglas, and Peter Cullen have all been categorized as being a close copy to the style of LaFontaine, and are sometimes confused with LaFontaine. LaFontaine was admitted to Cedars-Sinai Medical Center in Los Angeles, California with a blood clot in his lungs on August 22, 2008, and was reported as being in critical condition the following Tuesday. His family made a public appeal on the Mediabistro.com site. LaFontaine died September 1, 2008 following complications from pneumothorax.

LaFontaine is survived by his wife, the singer and actress Nita Whitaker, and three daughters Christine, Skye and Elyse.