For 1966, the Chevrolet Chevelle Series received new body designs consisting of front fenders that protruded forward, new body contour lines, new rear body cove treatment, an aluminum grille that appeared wider.

The Chevelle line, for 1966, consisted of the base level Chevelle 300, Chevelle 300 Deluxe, Chevelle Malibu, and Chevelle SS-396 series. The base-level Chevelle was available as a 2- and 4-door sedan. To help distinguish it from its upper-trim level siblings, it had very little ornamentation. There were fender series emblems, venti-pane frames, moldings around the windshield and rear window, four headlamps with anodized aluminum bezels, front bumper mounted park/turn lights, small hubcaps, and a single-unit rear light with built-in back-up lights. Other features included a rear cove Chevelle nameplate and grille outline moldings.

Chevrolet produced a total of 28,600 Chevelle 300s with the majority being fitted with six-cylinder engines. The six-cylinder powerplant was a 192 cubic-inch unit that offered 120 horsepower and features a Rochester one-barrel carburetor and hydraulic valve lifters. The overhead-valve V8 displaced 283 cubic-inches and offered nearly 200 horsepower. Just, 5,300 examples of the V8 were fitted into the engine bay of the Chevelle 300 Series. Pricing for the 4-door sedan began at $2,200 while the 2-door version was $2,175.

A Chevelle 300 Deluxe Series added full-length bodyside moldings, rear fender nameplates, and painted rear quarter reveal moldings. They also had tailgate molding and an emblem on the station wagon body styles. Inside, the 300 Deluxe had a dual-spoke steering wheel with a horn ring. They had a color-keyed upper instrument panel with a lower panel trim strip. The armrests in the rear seats had built-in ashtrays. The interiors were upholstered in cloth and vinyl.

Pricing for the 300 Deluxe began at $2,240 for the 2-door version. The station wagon was the most expensive body style, begging at $2,550. In total, Chevrolet sold 37,500 examples of their 300 Deluxes (no including station wagons). Again, the majority were powered by six-cylinder engines, with 10,500 being fitted with a V8.

The very popular Chevelle Malibu accounted for 241,500 sales (no including the station wagons) in 1966. Unlike the other series, the Malibu range was mostly powered by V8s, accounting for 189,300 units. The Malibu line included the items found in the base 300 and Deluxe series, plus additional design changes and amenities. They had wheelhouse moldings, a slender body sill, and Malibu rear fender nameplates. Other distinguishing features included a hood window-split molding, a rear cove emblem with Chevrolet script above the deck lid. There was a rear cove outline molding surrounding the single-unit rear lights, which had built-in back-up lamps. The station wagons had vertical light units and full-width molding and tailgate Chevelle nameplate.

Inside, the Malibus had cloth and vinyl upholstery. There were a dual-spoke steering wheel and a black crackle-finish on the instrument panel upper section. Other amenities included a rearview mirror and a glove compartment light.

Bodystyles included a station wagon, sedan, 2- and 4-door hardtop, and a convertible.

For the performance enthusiasts, Chevrolet offered the Chevelle SS-396. These Super Sport models had SS-396 grille and rear cover emblems, Super Sport script on the rear fenders, and twin simulated air intakes. They also had color-accented body sill, unique wheel covers, five nylon red-stripe tires, and rear fender lower moldings. The interiors were all vinyl with a bench front seat. These vehicles were available as either a 2-door hardtop or a convertible.

Powering the SS-396 was an overhead valve V8 displacing 396 cubic-inches and delivering an impressive 325 horsepower. They had a down-draft four-barrel carburetor, five main bearings, and featured hydraulic valve lifters. They rode on 7.75x14 inches and had a heavy-duty three-speed gearbox with floor shift controls.