Regarded as the most sophisticated of the early Monaro models, the HG is today one of the rarest and most sought-after of the Holden coupes. Released on the 26 July 1970, the HG Monaro was the last of the original coupe design concept. The HG had cleaner lines, with brightwork reduced and some re-designed. It sported different striping which was known as sidewinder stripes which ran along the top edge of the fenders, under the windows and finishing just before the rear pillar.

For the HG GTS, the GTS badges now featured black paint fill, it received new black-out paint on the rocker panels, with the GTS 350 getting bold treatment with new sidewinder stripes and bonnet scoop black-outs. GTS 350 designations now featured gutsier decals on the fenders and boot lid. The taillights had a cleaner look and the grille was redesigned.

Manual HG GTS 350 retained the suspension from the HT GTS 350. Other upgrades included thicker, HT GTS 350 style, power front disc brakes, now standard for all V8 and the 6-cylinder Monaro GTS. The HG would be the final model for the generation and the last to use the original body shell.

The HG range produced a total of 155,787 units which included 14,437 Monaro GTS coupes. The HG GTS 350 manual, with its very crisp driving feel and Salisbury limited slip differential, stood as the definitive road car for several Monaro generations.