The GMT900 is a General Motors full-size pickup and SUV platform used from the 2007 to 2014 model years. The platform was introduced at the 2006 North American International Auto Show, as the replacement for the GMT800 platform. The first GMT900 vehicle introduced was the next-generation Chevrolet Tahoe.

The Chevrolet Tahoe, and its badge-engineered GMC Yukon counterpart, are full-size SUVs and other trucks from General Motors, offered since 1994 and 1991, respectively. Since 1982, Chevrolet and GMC sold two different-sized SUVs under their "Blazer" and "Jimmy" nameplates, by introducing the smaller S-10 Blazer and GMC S-15 Jimmy for the 1983 model year, below the full-size Blazer and Jimmy models. This situation lasted into the early 1990s. GMC first rebadged the full-size Jimmy as the "Yukon" in 1991. Chevrolet however waited until 1994, when they rebadged the redesigned mid-size S-10 Blazer the "new Blazer," while renaming the full-size Blazer as the "Tahoe." The name Tahoe refers to the rugged and scenic area surrounding Lake Tahoe in the western United States, and was originally used as a trim level on S-10 models. The name Yukon refers to the Yukon territory of northern Canada.