The Beaumont story can be a little confusing but starts with another Canadian marque, Acadian, in 1962. Acadian had been created so that Canadian Pontiac-Buick dealers had a sub-compact to sell. The Chevy II was re-badged and given some trim differences to be sold as an Acadian. The styling was similar to a Pontiac but it was never sold as a Pontiac. There where three different trim levels, base, Invader, Beaumont. The Beaumont was the top of line model.
For 1964 things changed as Beaumont became its own model and the top of the line Chevy II based Acadian was renamed Canso. The intermediate Acadian Beaumont was sold from 1964 to 1965 and was a Canadian variant on the Chevrolet Chevelle. There were minor exterior styling differences such as split grill, badges and unique tail lights as well as the use of a Pontiac dash from the LeMans.
For 1966 Beaumont became its own marque but still based off the Chevelle. Chevrolet frames and power trains were used so the usual inline sixes, small and big block V8s were on offer. Trim lines included Custom, Deluxe and SD. SD (Sport Deluxe) being the performance option and equivalent Chevrolet’s SS. The Pontiac LeMans replaced the Beaumont after 1969 and that was the end of the Beaumont name and marque. Interestingly Beaumonts where not an Canadian exclusive as they where assembled in Africa and Chile as well as also sold in Puerto Rico.
Some vintage ads: