The Impala name was first used for the full-sized 1956 General Motors Motorama show car that bore Corvette-like design cues, especially the grille. It was named Impala after the graceful African antelope, which was used as the car's logo. Painted emerald green metallic, with a white interior, the Impala concept car featured hardtop styling. Clare MacKichan's design team, along with designers from Pontiac, started to establish basic packaging and dimensions for their shared 1958 General Motors "A" body in June. The first styling sketch that directly influenced the finished Chevrolet automobile was seen by General Motors Styling Vice President Harley Earl in October. Seven months later the basic design was developed. For 1958 GM was promoting their 50th year of production, and introduced anniversary models for each brand; Cadillac, Buick, Oldsmobile, Pontiac, and Chevrolet. The 1958 models shared a common appearance on the top models for each brand; Cadillac Eldorado Seville, Buick Limited Riviera, Oldsmobile Starfire 98, Pontiac Bonneville Catalina, and the Chevrolet Bel-Air Impala.The Impala was introduced for the 1958 model year as top-of-the-line Bel Air hardtops and convertibles. From the windshield (A) pillar rearward the 1958 Bel Air Impala differed structurally from the lower-priced Chevrolet models. Hardtops had a slightly shorter greenhouse and longer rear deck. The wheelbase of the Impala was longer than the lower-priced models, although the overall length was identical. Interiors held a two-spoke steering wheel and color-keyed door panels with brushed aluminum trim. No other series included a convertible.The 1958 Chevrolet models were longer, lower, and wider than their predecessors. The 1958 model year was the first with dual headlamps. The tailfins of the 1957 were replaced by deeply sculptured rear fenders. Impalas had three taillights each side, while lesser models had two and wagons just one. The Impalas included crossed-flag insignias above the side moldings, as well as bright rocker moldings and dummy rear-fender scoops.
As part of a GM economy move the 1959 Chevrolet Impala was redesigned to share bodyshells with lower-end BuicksOldsmobiles, and Pontiacs. Using a new X-frame chassis the roof line was 3 inches lower, bodies were 2 inches wider, the wheelbase was 1-1/2 inches longer, and curb weight increased. Flattened tailfins protruded outward, rather than upward. The taillights were a large "teardrop" design at each side, and two slim-wide, nonfunctional front air intake scoops were added just above the grille.The 1960 Impala models reinstated three round taillights on each side, and a white band running along the rear fenders. The 1960 Impala models reinstated three round taillights on each side, and a white band running along the rear fenders. The Impala was restyled on the GM B platform for the first time for 1961. The new body styling was more trim and boxy than the 1958–1960 models. Sport Coupe models featured a "bubbleback" roof line style for 1961, and a unique model, the 2-door pillared sedan, was available for 1961 only. It was rarely ordered. A "Super Sport" (SS) option debuted for 1961. This was also the last year the top station wagon model would have the Nomad name. Power brakes were $43. The 1962 model featured new "C" pillar styling for all models except the 4-door hardtop. Sport Coupe models now featured the "convertible roof" styling, shared with other GM "B" full-size hardtop coupe, which proved popular. The "overhang" roof style of the sedans was replaced with a wider "C" pillar with wraparound rear window. The Beach Boys produced a hit single, "409", referring to the Chevrolet, which became an iconic song for these cars. Impalas again featured premium interior appointments, plusher seats could be done by the dealerships on customer request. And more chrome trim outside, including a full-width aluminum-and-chrome panel to house the triple-unit taillight assembly. Super Sport (SS) models featured that panel in a special engine-turned aluminum, which was also used to fill the side moldings, making the SS more distinctive in appearance. The Impala also gained the top trim station wagon body design, in place of the Chevrolet Nomad model. However, unlike the passenger cars, Impala wagons had dual-unit taillights. Due to reliability problems, the optional Turboglide automatic transmission was discontinued, leaving Powerglide the only automatic transmissionavailable until 1965. A new radio was optional.