The Alfa Romeo GT was produced from 2003-2010; a total of 80,832 were built. The GT was introduced at the Geneva Motor Show in 2003, and it went on sale in Italy in January 2004. All cars were built at the central Italian Pomigliano plant, along with the 159 and 147. Like the latter, the GT utilized the 156 platform, with a Bertone-styled coupe body.

Most mechanical components are directly taken from the 147/156, including the front and rear suspension. The car's interior is based on the 147, and shares many parts. The GT uses the same instrument panel, air conditioning/heating system and electrical components. The cars came with either a 1.8 or 2.0 gasoline engine, a 1.9 turbodiesel, or a 3.2L V6.

The GT is the sports car of the Alfa Romeo line, and takes its place alongside the GT Brera; both cars are seen as replacements for the GTV. It's highly unusual for a car maker to build two midsize sports coupes at the same time, and many could be led to think that the cars directly compete with one another.

Alfa Romeo introduced a 1.9L JTD engine with a limited-slip differential, and it also added a trim level known as "Black Line". In 2008, the company introduced the "Cloverleaf" model, with lowered suspension, a body kit, 18" wheels, and new trim level. It was only available in black, Alfa red, and blue.