The Cadillac Series 65, after the Series 60, represented Cadillac's second, and, being built on the C-body instead of the B-body, somewhat physically larger entry into the mid-priced vehicle market when it appeared in 1937.

In 1937 it was offered in only one body style, a 4-door 5-seat sedan, built by Fisher on the same 131.0 in (3,327 mm) wheelbase as used by the Cadillac Series 70 and the Buick Roadmaster.

The car had Bendix dual-servo brakes, "Knee-Action"[1] independent suspension in front and a Stromberg carburetor ('37: AA-25; '38: AAV-25) with an electric choke.

The rear of the body had rounder corners and more smoothly blended lines.

New chassis details included a column gear shift, horns just behind the grille, battery under the right hand side of the hood, transverse muffler just behind the fuel tank, wheels by a different manufacturer, "Synchro-Flex" flywheel, hypoid rear axle and the deletion of the oil filter.