Only 10,532 GTOs were sold in 1971. 534 of those were equipped with the 455 motor & TH 400 trans. The 4 speed was not available with the 455 motor. It was, however available with the 455HO motor.

The 1971 GTO had a modest facelift with wire-mesh grilles, horizontal bumper bars on either side of the grille opening, more closely spaced headlamps, and a new hood with the dual scoops relocated to the leading edge, not far above the grille. Overall length grew slightly to 203.3 inches (516 cm). A new corporate edict, aimed at preparing GM for no-lead gasoline, forced an across-the-board reduction in compression ratios. The Ram Air engines did not return for 1971.

The standard GTO engine was still the 400 CID V8, but now with 8.2:1 compression. Power was rated at 300 hp (220 kW) at 4,800 rpm and torque at 400 lb·ft (542 N·m) at 3,600 rpm.

An engine option was the 455 CID V8 with four-barrel carburetor, 8.4 to 1 compression ratio and 325 hp (242 kW), only available with the automatic transmission.

The top GTO engine for 1971 was the new 455 HO with 8.4 compression, rated at 335 hp (250 kW) at 4,800 rpm and 480 lb·ft (651 N·m) at 3,600 rpm.

Motor Trend tested a 1971 GTO with the 455 HO, four-speed transmission, and 3.90 axle, and obtained a 0-60 mph time of 6.1 seconds and a quarter mile acceleration of 13.4 seconds at 102 mph (164 km/h).

The Judge returned for a final year, now with the 455 HO as standard equipment. Only 374 were sold before The Judge was discontinued in February 1971, including 17 convertibles—today the rarest of all GTOs.