The Power Mac G4 is a series of personal computers designed, manufactured, and sold by Apple Computer from 1999 to 2004 as part of the Power Macintosh line. Built around the PowerPC G4 series of microprocessors, the Power Mac G4 was marketed by Apple as the first "personal supercomputers", reaching speeds of 4 to 20 gigaFLOPS. This was the first existing Macintosh product to be officially shortened as "Mac", and is the last Mac able to boot into classic Mac OS.

The Power Macintosh, later Power Mac, is a family of personal computers designed, manufactured, and sold by Apple Computer, Inc as the core of the Macintosh brand from March 1994 until August 2006.