GMT (General Motors Truck) is a nomenclature used by General Motors to designate multiple vehicle platforms. In use since the early 1980s, the GMT nomenclature is used for light trucks, full-size SUVs, and vans, along with several medium-duty trucks. With only a few exceptions, nearly all GMT vehicles use body-on-frame construction, along with rear-wheel drive (or all-wheel drive) powertrain configurations.

Primary applications of the platform – those that are equivalent in basic RWD/frame structure to each other – existed from 1981 to 1989, and again since 2018.

Pickups and SUVs have been the main vehicles underpinned by GMT platforms, being involved for the entirety of the platform's existence.

1. GMT400 –Chevrolet C/K and variants, 1988 – 2002
2. GMT800 –Chevrolet Silverado and variants, 1999 – 2007
3. GMT900 – Chevrolet Silverado and variants, 2007 – 2014
4. GMTK2XX – Chevrolet Silverado and variants, 2014 – 2019
5. GMTT1XX – Chevrolet Silverado and variants, 2019–present

1. GMT325 –Chevrolet S-10 and truck rebadgings, 1982 – 2012
2. GMT330 –Chevrolet S-10 Blazer and SUV rebadgings, 1983 – 2012
3. GMT355 –First-gen. Chevrolet Colorado and truck rebadgings, 2004 – 2012
4. GMT360 –Chevrolet TrailBlazer and rebadgings, 2002 – 2009
5. GMT700, laterGMT31XX –Second-gen. Chevrolet Colorado, 2012–present
6. GMT700, laterGMT31XX –Second-gen. Chevrolet TrailBlazer SUV, 2012–present

In contrast to the Hummer H1–designed and assembled by AM General, theHummer H2 andHummer H3 were developed by GM, receiving their own platform designations. Designated theGMT825, the H2 was derived from the GMT820 (Chevrolet Tahoe/GMC Yukon), with its own midsection frame design and a rear frame shared with the 2500-series GMT800 pickup trucks.^[1]

The H3 SUV was designated theGMT345, a close variant of the GMT355 (Chevrolet Colorado/GMC Canyon). The 2009-2010 H3T pickup truck was designated as theGMT745, adopting a nomenclature closer in line with the GMT700 used by the later second-generation Colorado/Canyon.

The 1996Chevrolet Express/GMC Savana replaced the previous G-series Van/Vandura, adopting theGMT600 designation. As part of a model update and revision for 2003, GM changed the Express/Savana toGMT610, which remains in use. The model line competes with theFord Transit, andFord E-Series (dependent on configuration),Mercedes-Benz/Freightliner Sprinter,Dodge Ram Wagon, and theRam ProMaster (cargo van only).

For 1990, theChevrolet Kodiak/GMC TopKick medium-duty trucks adopted theGMT530 designation (sharing the cab of the GMT400 trucks). For 2003, the line was redesigned, becoming theGMT560 platform (sharing a version of the GMT610 cab). After the 2009 model year, General Motors ended medium-duty truck production.

Since 2018, a medium-duty version of the GMTK2XX has been produced in a joint venture with Navistar International.

While the aforementioned platforms are the ones model commonly referred to as GMT platforms, there have been other instances of the name being applied which are not for RWD and/or body-on-frame vehicles.

For 1990, GM unveiled its firstminivans, all of which were underpinned by thefirst generation of the U platform. This platform was given the alternate name ofGMT199 shortly thereafter, beginning the pattern of expanded use for the GMT platform name. This pattern was kept for the 1996second-generation and 2005third-generation GM minivans, called theGMT200 andGMT201 platforms, respectively. With the 2010 introduction of thefourth-generation U platform, the designation GMT510 was planned for use. However, all of the GM minivans (save for the China-exclusiveBuick GL8) were dropped, ergo the name went unused.

For its production from 2006 to 2011, the compactwagon-bodiedChevrolet HHR rode on the Delta platform. Despite this, it was internally given the designation ofGMT001.

In 2001 and 2002, thePontiac Aztek andBuick Rendezvous were introduced, respectively. These were built upon a shortened version of the U platform which underpinned GM's minivans. As such, they were given theGMT 250 andGMT 257 names respectively. For 2003,Cadillac released their first crossover, the Sigma-basedfirst-generation SRX. Being a luxury model, it was given the alternate platform code ofGMT265. Thesuccessive generation SRX, on anentirely different platform, was calledGMT166. The relatedSaab 9-4X was calledGMT168.

In 2004, with the release of thefirst-generation Chevrolet Equinox, theGMT 191 name was internally used to refer to it. Consequently, theGMT190 name was retroactively applied to thesecond-generation Chevrolet Tracker, which could be considered one of the Equinox's predecessors.GMT192 was used to refer to thePontiac Torrent, which was released a year later. The next application of this platform was calledGMT193, used exclusively for thesecond-generation Suzuki XL7, which was discontinued in 2009. The 2010second-generation Chevrolet Equinox, was calledGMT172. The relatedGMC Terrain was calledGMT177. In 2017, thethird-generation Equinox went on sale, though it did not use an alternate GMT designation for its platform, and simply used the latest Delta platform variantD2XX. This decision, along with the equivalent shifts for the Enclave and Traverse models in the same year, made for the end of the use of GMT-platform designations for models that are not RWD and body-on-frame.

For 2007, the release of the newSaturn Outlook andGMC Acadia, as well as the Lambda platform, occurred. Lambda itself was called theGMT960 series, with each individual vehicle it underpinned getting an alternate GMT-designation as well. The Outlook was givenGMT966, and the AcadiaGMT968. The next year, theBuick Enclave andChevrolet Traverse were introduced, and givenGMT967 andGMT561, respectively. Despite numerical similarity in nomenclature of these platforms to the GMT900/GMT560 platforms, there was no further relation, as these models were actually more similar to the other GM crossover platforms.