The Pininfarina-styled 308 GTB was introduced at the Paris Motor Show in 1975 as a supplement to the Bertone-shaped Dino 308 GT4 and a replacement for the Dino 246. It was designed by Leonardo Fioravanti who had been responsible for some of Ferrari's most celebrated shapes to date such as the Daytona, the Dino and the Berlinetta Boxer. The 308 used elements of these shapes to create something very much in contrast with the angular GT4 2+2. The GTB/GTS was a 2-seater with sweeping curves and aggressive lines, and has become the most recognized and iconic Ferrari road car.

The targa topped 308 GTS was introduced in 1977 and was made famous on the television series Magnum, P.I.. Several cars were used, a new one for each season, most being auctioned off after filming. The first was a 1979 model with chassis number 28251.

The mechanically similar 308 GT4 shared much with the original Dino, and the 308. Both sit on the same tube-frame platform, with a 92 in (2,300 mm) wheelbase for the 308 GTB (the 308 GT4 has a longer wheelbase, it is a 2+2) , and 4-wheel double wishbone independent suspension. The V8 engine is a DOHC design, with four Weber 40DCNF carburetors. European versions produced 255 hp (190 kW) at 7,000 rpm (7700 rpm redline), but American versions were down to 240 hp (178 kW) at 6,600 rpm due to emissions control devices.

A notable aspect of the early 308 GTB was that, although still built by Carrozzeria Scaglietti, the 308's bodywork was entirely made of glass-reinforced plastic (or GRP), allowing a very light weight of 1,050 kg (2,315 lb). The engine borrowed its dry-sump lubrication from Ferrari's racing experience. This lasted until June, 1977, when the 308 was switched to steel, resulting in an, alleged, 150 kg (331 lb) additional weight. However, a steel-bodied GTB only weighs 12 kg (26 lb) more that its fiberglass body counterpart.^[ All steel versions of the 308 GTS have a conventional wet-sump engine while GTB models retained the dry sump lubrication until 1981.

The 308 models are the most common historical Ferrari models, with over 12,000 produced. However, only 712 of the first Fiberglass dry-sump version were made, which are now the most sought-after by collectors. The 308 models are embraced by Ferrari fans and critics today. In 2004, Sports Car International named this car number five on the list of Top Sports Cars of the 1970s.

Test performance, 308 GTB (GRP): Weight (kerb with 74 l fuel) 2,778 lb (1,260 kg), acceleration 0-100 mph 15.0s, 0–100 km/h 6.5 s, 100–200 km/h 17.8s, top speed 159 mph (256 km/h).