The Seville was introduced as a downsized 1976 Cadillac in April 1975.

• It appeared in dealer showrooms the first day of May.
• It was based on the GM front engine/rear drive "X" car platform used for the Chevrolet Nova and its derivatives such as Oldsmobile Omega, Pontiac Ventura, and Buick Apollo.
• The exterior panels were, however, exclusive to Cadillac and the equipment and trim level was as rich as possible.
• Included at a base price of $12,479 were
  • padded vinyl roof
  • air conditioning
  • Automatic Level Control
  • power seats
  • power windows
  • power door locks
  • AM/FM stereo
  • leather or special cloth upholstery
  • Tilt & Telescope steering wheel
  • chimes
  • GR78-15/B steel-belted radial whitewall tires.
• Sevilles came only as four-door sedans with crisp, angular-curved styling that was purely modern.
• Square headlamps, wraparound cornering lights, and an eggcrate grille with narrow vertical center division bar were seen.
• The base powerplant was a 350-cid Oldsmobile product, to which electronic fuel injection was added.