The Cessna Model 120 prototype, first flown on 28 June 1945, represented the company's attempt to capture a share of the post-war market for personal lightplanes. A two-seat cabin monoplane with a strut-braced high-set wing, it was the progenitor of derived models that ramained in production until the late 1980s. Structure was all-metal, except for fabric-covered wings, the landing gear was of fixed tailwheel type introducing cantilever spring steel main units, and the enclosed cabin provided two seats side-by-side and dual controls as standard. Powerplant comprised an 63kW Continental engine, and the higher power of this unit by comparison with competing types, plus a low price tag, ensured that Cessna gained an unexpectedly large measure of sales success.

The Model 120, a basic aircraft, was complemented by a 'de luxe' Model 140 which provided as standard manually actuated trailing-edge flaps, extra cabin windows and a full electrical system. When production of the Models 120 and 140 ended in 1950 more than 2,200 Model 120s and 5,000 Model 140s had been built.