The launch of the Royale in 1978 could be argued to be the start of General Motors attempt to unite the Vauxhall and Opel vehicle ranges. Essentially a badge-engineered version of the Opel Senator and Monza, with a different front grille, the Royale was even built in the Germany factory.

Initially only available with a 2.8 engine fitted with a carburettor, by 1980 the Royale had gained fuel injection. The engine was similar to that used in the Opel Admiral, Commodore and Senator. The Royale, with its plush, gold velour interior trim, was available until 1984 when it was replaced by the Vauxhall Senator.