PowerPC G4 is a designation formerly used by Apple and Eyetech to describe a fourth generation of 32-bit PowerPC microprocessors. Apple has applied this name to various (though closely related) processor models from Freescale, a former part of Motorola. Motorola and Freescale's proper name of this family of processors is PowerPC 74xx.

Macintosh computers such as the PowerBook G4 and iBook G4 laptops and the Power Mac G4 and Power Mac G4 Cube desktops all took their name from the processor. PowerPC G4 processors were also used in the eMac, first-generation Xserves, first-generation Mac Minis, and the iMac G4 before the introduction of the PowerPC 970.

Apple completely phased out the G4 series for desktop models after it selected the 64-bit IBM-produced PowerPC 970 processor as the basis for its PowerPC G5 series. The last desktop model that used the G4 was the Mac Mini which now comes with an Apple M1 processor. The last portable to use the G4 was the iBook G4 but was replaced by the Intel-based MacBook. The PowerBook G4 has been replaced by the Intel-based MacBook Pro.

The PowerPC G4 processors are also popular in other computer systems, such as the AmigaOne series of computers and the Pegasos from Genesi. Besides desktop computers the PowerPC G4 is popular in embedded environments, like routers, telecom switches, imaging, media processing, avionics and military applications, where one can take advantage of the AltiVec and its SMP capabilities.