The school bus version of the Gillig Phantom, referred to as the Gillig Phantom School Bus, was introduced in 1986. Production ended after 1993, after none had been sold in 1991 or 1992. This model was produced only in the 96" body width (standard for all school buses), and was available in 37 feet (78 passenger) and 40 feet (84 passenger) lengths. Three engines were available: the Caterpillar 3208 (until 1990), the Caterpillar 3116 (1991–1993), and the Detroit Diesel 6V92TA. Two transmissions were available: The Allison MT-643 and the Allison HT-740. Manual transmissions were also available in the early years of this bus, including the Spicer CM5252A and 6252B and Fuller T11605M 5-speeds and Fuller Roadranger RT6610 and RT11610 10-speeds; however, many school districts opted for the Allison automatic. A kneeling device was an option, which was very rare for a school bus. Just like on the transit version, the kneeling device allowed the front of the bus to be lowered while the bus was loading or unloading passengers.
The Phantom School Bus had these modifications over the transit version of the Phantom:
- The left-side windshield glass was mounted vertically instead of being sloped inward.
- The (single) curb-side entry door was narrower in width since the stairwell did not need to accommodate a wheelchair lift.
- A rear exit window and left-side emergency exit door were added.
- Dual headlights were fitted instead of quad headlights. These were optional for the transit version.
- Red warning lamps were fitted (amber lamps fitted for Phantoms sold outside of California)
- Larger sideview mirrors were fitted along with cross-view mirrors to meet regulations for school buses.
Much like its predecessor, the Transit Coach, the Phantom School Bus was marketed primarily for West Coast operators. Although initially well-received, sales dropped off and production ceased in 1993 (no Phantom School Buses were sold in 1991 or 1992).