The first use of the Seville name was on a hardtop version of the 1956 Cadillac Eldorado convertible. Four Eldorado Seville 4-door hardtops were built in 1957, but it is the outlandish tailfins found on the 1959 model that are most remembered. 1960 was the last year for the Eldorado Seville.
Various names were considered for what became the next generation Seville. Resurrection of the LaSalle nameplate was seriously considered, but it was decided that given that LaSalle had been used for entry-level sub-Cadillacs in the past; it would create confusion in the marketplace among those who recollected the context of the names previous use.
The Seville introduced in 1975, was Cadillac's answer to the rising popularity of luxury imports in the US from Europe, such as Mercedes-Benz and BMW. Historically, these imported luxury cars had been cheaper, less luxurious and significantly smaller than Cadillacs. Over time they had evolved, becoming quite luxurious and even more expensive than the much larger Cadillacs. As the market share of these imports continued to climb, it became obvious that the traditional American automotive paradigm of "bigger equals better" was no longer in full effect in the marketplace. The Seville became the smallest and most expensive model in the lineup, turning Cadillac's traditional marketing and pricing strategy upside down.
Initially based on the rear-wheel drive X-body platform that underpinned the Chevrolet Nova (a unibody with a bolt-on subframe — this layout was common with both GM X and F bodies), the Seville's unibody and chassis were extensively re-engineered and upgraded from that humble origin and it was awarded the unique designation of "K-body". Cadillac stylists added a crisp, angular body that set the tone for GM styling for the next decade, along with a wide-track stance that gave the car a substantial, premium appearance. A wide chrome grille flanked by quad rectangular headlamps with narrow parking and signal lamps just below filled the header panel, while small wrap-around rectangular tail lamps placed at the outmost corners of the rear gave the appearance of a lower, leaner, and wider car. The wrap-around taillights might have came from a design sketch of a Coupe DeVille concept which was rejected (the concept can be seen in the March 2008 issue of Collectible Automobile detailing the 1977 GM full-size cars).