The Oldsmobile 98 is the full-size flagship model of Oldsmobile that was produced from 1940 until 1942, and then from 1946 to 1996. The name – reflecting a "Series 90" fitted with an 8-cylinder engine – first appeared in 1941 and was used again after American consumer automobile production resumed post-World War II. It was, as it would remain, the division's top-of-the-line model, with lesser Oldsmobiles having lower numbers such as the A-body 66 and 68, and the B-body 76 and 78.

For 1959, the Oldsmobile line-up was completely redesigned. Oldsmobile offered four body styles on an exclusive 3.208 mm wheelbase: a four-door sedan, a two-door hardtop, a four-door hardtop and a convertible. 

The 6.5 L, the largest first generation Rocket V8, was used from 1959 until 1964.

Since it was the top-line Oldsmobile, the series had the most technologically advanced items available, such as the Hydramatic automatic transmission, the Autronic Eye, an automatic headlight dimmer, and Twilight Sentinel (a feature that automatically turned the headlights on and off via a light sensor and a delay timer, as controlled by the driver), and the highest-grade interior and exterior trim.