The Rover 75 started life as part of a group of three new designs for Rover Group under the guidance of Richard Woolley; a large saloon codenamed Flagship, a smaller vehicle (with the codename of Eric), and the 75. Of these only the 75 concept progressed. The initial aim was to reskin the Rover 600 (launched in April 1993) but following the BMW takeover in 1994, it was quickly decided that this platform would not be reused but replaced by an entirely new model, scheduled for launch in the late 1990s.

Work on the new model, codenamed R40, progressed with little operational interference from BMW; the styling received an enthusiastic response from the management and both companies believed the classical look would be the ideal direction for Rover. The Rover 75 debuted at the Birmingham Motor Show on 20 October 1998 and went on sale in June 1999 having been extensively tested by the motoring press.

The 75 featured a range of petrol and diesel engines from 1.8- to 2.5-litres. Petrol engines provided were Rover's 4-cylinder K series in 1.8-litre guise and the quad cam KV6, offered in either short-stroke 2.0 or revised 2.5-litre formats. The 2.0-litre was later dropped on introduction of the 1.8-litre turbo for emissions reasons. A diesel engine was provided through BMW Group.

Assembly originally took place at Cowley but in 2000, following the sale of the company by BMW to Phoenix Venture Holdings, production was moved to Longbridge in Birmingham. 2001 saw the introduction of the Rover 75 Tourer , swiftly followed by the MG ZT and MG ZT-T, more sporting interpretations of the model, differentiated by modified, sporting chassis settings and colour and trim derivatives. Between 2000 and 2003, there were few changes to the range: the most significant was the replacement of the 2-litre V6 engine by a low-pressure-turbocharged version of the 1.8-litre 4-cylinder engine. The introduction of the 'greener' 1.8-litre turbo greatly benefited British company car drivers who are taxed on carbon dioxide emissions. A customisation programme, Monogram, was launched, allowing buyers to order their car in a wider range of exterior paint colours and finishes, different interior trims and with optional extras installed during production. Rather surprisingly, it was offered for sale in Mexico, making it the first Rover to be sold in the Americas since the Sterling.

In April 2000 it was Britain's fifth-most popular new car. It was still selling reasonably well at the time of MG Rover's bankruptcy in April 2005, and a small number of unsold 75s were still in stock in early-2007.