The Blazer was first introduced as a 1969 model. It was created in response to Ford's Bronco that was first made in 1966. The Blazer was much larger overall than the Bronco. The Blazer's fiberglass roof came off all the way up to the windshield. It's wheelbase was 104 inches. This body style lasted through the 1972 model year. In 1973 GM redesigned the Blazer and Jimmy (along with the pickups) and it took on a more boxy shape. The wheelbase became 106.5 inches.

In 1976, although the body remained essentially the same, Blazers and Jimmys now had a fixed steel half cab. The fiberglass roof still came off, but only up to the back of the front seats. A new integral hidden roll bar was added into the steel half cab.

In 1992 the body, chassis, and interior were completely redesigned. The pick-ups had already changed over to this body style in 1988. The front suspension was now independent. There was no longer a fiberglass top that could be removed. In essence, the Blazer was unrecognizable as a Blazer. It would keep the Blazer name until 1995, when GM now called it the Tahoe. The original Blazer and Jimmy names that were used since 1969 were now only used on the half-size sport utilities (originally called the S-10's) that had only been around since 1983.