The Dolomite was the final addition to Triumph's small-car range (codenamed "Project Ajax"), which had started in 1965 with the Triumph 1300. Designed to be a replacement for the rear-wheel drive Triumph Herald, the 1300 was originally fitted with a 1,296 cc (79 cu in) engine and front-wheel drive. The later model, introduced in September 1970 as the Triumph 1500, featured a remodelled front and rear, styled by Michelotti, and a larger 1,493 cc (91 cu in) engine.

Triumph were however dissatisfied with the market performance of the 1300; although it had been moderately successful, the higher price and greater complexity meant sales never reached the levels of the simpler and cheaper Herald which preceded it. In an attempt to improve matters, the car was comprehensively re-engineered. Launched in September 1970, the Triumph Toledo was a cheaper and more basic variant of the 1300, but with conventional rear-wheel drive. This new model was assembled alongside the now larger-engined front-wheel drive version (the Triumph 1500) which was launched at the same time as the Toledo.