The first-generation Toyota Tundra (factory index XK30) was introduced in May 1999 as a 2000 model year vehicle, replacing the T100. It was the first full-size pickup from a foreign brand to be built in North America at the Indiana plant. Unlike the T100, the Tundra was offered from the start with a V8 engine—a 4.7-liter 2UZ-FE producing 245 hp, providing performance on par with American competitors. A 3.4-liter V6 (190 hp) remained the base option. The truck was initially available in Regular Cab and Access Cab configurations, the latter featuring rear-hinged half doors.

In 2004, a Double Cab version was added to the lineup, featuring a longer wheelbase and a spacious rear seating area, making the truck much more versatile. For the 2005 model year, the Tundra received a mechanical update: the base V6 was replaced by a new 4.0-liter engine (236 hp), and the 4.7-liter V8 gained VVT-i technology, boosting output to 282 hp. A new 5-speed automatic transmission was also introduced for the V8 models. The first generation laid a strong foundation for Toyota's success in the full-size truck segment.