The Power Macintosh G3 represents Apple's first step, towards eliminating redundancy and complexity in the product line. They did this by replacing eight Power Macintosh models (and the Twentieth Anniversary Macintosh) with three: Desktop and Mini Tower models for professional and home use, and an All-In-One model for education.

The introduction of the Desktop and Mini Tower models coincided with Apple starting to sell build-to-order Macs directly from its website in an online store, which was unusual for the time, as Dell was the only major computer manufacturer doing this. Apple's move to build-to-order sales of the Power Macintosh G3 also coincided with the acquisition of Power Computing Corporation.

The Power Macintosh G3 is named for its third-generation PowerPC chip, and introduced a fast and large Level 2 backside CPU cache, running at half processor speed. These machines benchmarked significantly faster than PCs of similar CPU clock speed at launch, which prompted Apple to create the "Snail" and "Toasted Bunnies" television commercials. Magazine benchmarks showed the G3/266 CPU, outperforming the 350 MHz PowerPC 604ev chip in the Power Macintosh 9600 as well.

Two generations of the Power Macintosh G3 were released. The first generation, known colloquially (but not officially) as "Beige" was introduced at a special event on November 10, 1997. The second generation, known officially as "Blue and White", was introduced at MacWorld San Francisco on January 5, 1999. Its replacement, the Power Mac G4, was introduced in August of the same year.