Pepsi One, corporately styled Pepsi ONE (so named because it contains one calorie per eight-fluid ounce [230 ml] serving), is a sugar-free cola, marketed by PepsiCo in the United States as an alternative to regular Pepsi and Diet Pepsi.
On June 30, 1998, the artificial sweetener acesulfame potassium (Ace-K) was approved for use by the Food and Drug Administration. PepsiCo responded within one hour, announcing the introduction of Pepsi One (which reached store shelves the following October). This new variety was based upon an earlier product (sold in other countries) called Pepsi Max, but it featured a formula and flavor profile developed specifically for the U.S. market.
The launch of Pepsi One included an advertising campaign featuring the slogan "just one calorie." Subsequently, comedian Tom Green appeared as the spokesperson.
Before 2012, Pepsi One was the only Pepsi variant to include the 2005-2008 logo, while all the other Pepsi variants had the 2008-present logo. Pepsi One's logo was later modernized with the other flavors.
On April 7, 2010 it was announced that Pepsi One would be the title sponsor of Toyota Speedway at Irwindale's Super Late Models, the track's top division. The series will be called the NASCAR Pepsi One Super Late Models.