The 1959 Cadillac is remembered for its huge sharp tailfins with dual bullet tail lights, two distinctive rooflines and roof pillar configurations, new jewel-like grille patterns and matching deck lid beauty panels. In 1959 the Series 62became the Series 6200. De Villes and 2-door Eldorados were moved from the Series 62 to their own series, the Series 6300 and Series 6400 respectively, though they all, including the 4-door Eldorado Brougham (which was moved from the Series 70 to Series 6900), shared the same 130 in (3,302 mm) wheelbase. New mechanical items were a "scientifically engineered" drainage system and new shock absorbers. All Eldorados were characterized by a three-deck, jeweled, rear grille insert, but other trim and equipment features varied. The Seville and Biarritz models had the Eldorado name spelled out behind the front wheel opening and featured broad, full-length body sill highlights that curved over the rear fender profile and back along the upper beltline region. Engine output was an even 345 hp (257 kW) from the 390 cu in (6.4 L) engine. Standard equipment included power brakes, power steering, automatic transmission, back-up lamps, windshield wipers, two-speed wipers, wheel discs, outside rearview mirror, vanity mirror, oil filter, power windows, six way power seats, heater, fog lamps, remote control deck lid, radio and antenna with rear speaker, power vent windows, air suspension, electric door locks and license frames. The Eldorado Brougham also came with Air conditioning, automatic headlight dimmer, acruise control standard over the Seville and Biarritz trim lines.
The 1960 Cadillacs had smoother, more restrained styling. General changes included a full-width grille, the elimination of pointed front bumper guards, increased restraint in the application of chrome trim, lower tailfins with oval shaped nacelles and front fender mounted directional indicator lamps. External variations on the Seville two-door hardtop and Biarritz convertible took the form of bright body sill highlights that extended across the lower edge of fender skirts and Eldorado lettering on the sides of the front fenders, just behind the headlamps. Standard equipment included power brakes, power steering, automatic transmission, dual back-up lamps, windshield wipers, two-speed wipers, wheel discs, outside rearview mirror, vanity mirror, oil filter, power windows, six-way power seats, heater, fog lamps, Eldorado engine, remote control trunk lock, radio with antenna and rear speaker, power vent windows, air suspension, electric door locks, license frames, and five whitewall tires. Technical highlights were finned rear drums and an X-frame construction. Interiors were done in Chadwick cloth or optional Cambray cloth and leather combinations. The last Eldorado Seville was built in 1960.
A different Eldorado Brougham was sold for 1959 and 1960. These cars were not quite so extravagantly styled but were very unusual pieces in themselves. Priced at $13,075, they cost $1 more, each, than their older siblings. The company contracted out the assembly to Pininfarina of Italy, with whom the division has had a long-running relationship, and these Eldorados were essentially hand-built in Italy. Ironically only now did it acquire Fleetwood wheel discsand doorsill moldings, presumably because the design work and final touches were still being done by Fleetwood. Discreet, narrow taillights integrated into modest tailfins, and a squared-off rear roof line with rear ventiplanes caused the Italian-built Brougham to contrast sharply to the rounded roof lines, and especially the new "rocketship" taillights and flamboyant fins of the standard 1959 Cadillacs, which are a feature only of that year. A vertical crest medallion with Brougham script plate appeared on the front fenders and a single, thin molding ran from the front to rear along the mid-sides of the body. It did not sport Eldorado front fender letters or body sill headlights. A fin-like crest, or "skeg," ran from behind the front wheel opening to the rear of the car on the lower bodysides and there were special crest medallions on the trailing edge of the rear fenders. The Brougham's styling cues would prove to indicate where standard Cadillac styling would head from 1960 through the early-mid-1960s. The standard equipment list was pared down to match those of other Eldorados, plus Cruise Control, Autronic Eye, air conditioning and E-Z Eye glass. The Brougham build-quality was not nearly to the standard of the Detroit hand-built 1957–1958 models, and thus the 1959–1960 Broughams did not sell as well as their forebears. However, collector interest and values for these cars remain high. The Eldorado Brougham was moved to its own unique Series 6900 for its remaining two years.
The 1960 Cadillac Eldorado Biarritz 6467E is featured as Maurice Minnifield's vehicle in the 1990s television series Northern Exposure.