The first generation was largely based on its predecessor, the 307, and utilized modified versions of that car's drivetrain and chassis.

[2] Launched as the replacement for the Peugeot 307 in most international markets, the new vehicle was based upon the old 307's chassis, but has new bodywork and is slightly longer and wider.

[7] The 308 HDi holds the Guinness world record of the most fuel efficient mainstream car currently in production, having averaged 3.13 litres per 100 kilometres (90 mpg‑imp; 75 mpg‑US) over a distance of 14,580 km (9,060 mi), but Peugeot ran foul of British advertising rules by referencing a fuel consumption of 126 mpg‑imp (2.24 L/100 km; 105 mpg‑US) in an advert for the car.

In May 2010, Peugeot announced the return of a GTi model (known as the GT in the United Kingdom), featuring a turbocharged 1.6 L engine with 200 bhp (149 kW; 203 PS).

[11] A station wagon concept version of the 308, the Peugeot 308 SW Prologue, was also unveiled at the 2007 Frankfurt Motor Show.

A facelifted 308 was released in May 2011, following the public launch at the 2011 Geneva Motor Show, with a new front end and minor changes to the rear of the vehicle.

There is a touch screen perfectly integrated with the centre console, instead of the traditional CD / MP3 and empty pockets.

[17] Peugeot presented a 2+2 coupé concept car development of the 308, the 308 RCZ,[18] at the 2007 Frankfurt Motor Show.

The final production model was unveiled at the 2009 Frankfurt Motor Show as the RCZ without the 308 name, and went on sale in the spring of 2010.

[21] It is built on the PSA EMP2 platform, shared with Citroën C4 Picasso, resulting in 140 kg (310 lb) weight loss compared to previous generation.

The 250 hp version had full LED headlights, an electronic limited slip differential, 18" alloys, keyless entry, stop/start technology, 11 mm lowered ride height, a coloured reversing camera and twin exhausts.

Additionally, the 270 hp version gets 380 mm Alcon front brakes, massaging leather/Alcantara bucket seats, a Torsen limited-slip differential and 19" lightweight alloy wheels.

In July 2020, a revised 308 was announced featuring a number of trim and colour changes, but most significantly, the introduction of the digital i-Cockpit which was first introduced on the Peugeot 3008.

Peugeot has also reduced its height by 20 mm (0.8 in) to create a sleeker silhouette and to achieve a lower drag coefficient of 0.28.

Other features offered as standard or optional include long-range blind-spot monitoring, 360-degree surround-view parking assistance with four cameras, rear cross-traffic alert, heating for the windscreen and steering wheel, and an E-call+ emergency call function.