The designation G5 refers to the computer's processor, the 64-bit PowerPC G5 processor. The iMac G5 is the last generation of iMac to use PowerPC processors.

The iMac G5, like its predecessors, was designed by Apple Industrial Design Group led by Jonathan Ive. The design of the iMac G5 was a logical continuation of the revolutionary iMac Flat Panel. They returned to the all-in-one principle and made it more compact. They did this by putting the computer behind the screen.

The white housing of the iMac G5 is made of polycarbonate. At the bottom of the housing is an aluminum grille, which is necessary for both cooling and the loudspeakers. The entire computer rests on an aluminum stand. Due to the stand, the display cannot be adjusted in height, nor can the display be rotated without moving the entire computer.

The flat back of the iMac G5 makes it possible to mount the computer on the wall. The aluminum stand on which the computer rests can be replaced by a mounting plate. Apple offered a special VESA Mount Adapter Kit as an option for this. Due to its convex back, the iMac G5 (iSight) cannot be hung on the wall or an arm via a VESA mounting plate.