The 1966 Trans-American Sedan Championship was the inaugural running of the Sports Car Club of America's Trans-Am Series auto racing series. It was open to FIA Group 1 and FIA Group 2 cars and was contested over seven races.[1] Manufacturers titles were awarded for both Over 2 Liter and Under 2 Liter cars with Ford and Alfa Romeo winning their respective class championships.[1] Horst Kwech and Gaston Andrey were subsequently named Drivers co-champions in 1980 when the SCCA retroactively named drivers championships for the series after the 1980 season.
The championship was contested over a seven race series.[1]Overall winner race winners are shown in bold.
The Dodge Dart of Bob Tullius won the Over 2 liter class at the opening race at Sebring International Raceway, while the Alfa Romeo GTA of Formula One driver Jochen Rindt won the Under 2 liter class and was placed first overall.[1]
Over the course of the championship Ford Mustangs won the Over 2 liter class at four races with Dodge Darts winning twice and Plymouth Barracuda once.[1] Alfa Romeo GTAs won the Under 2 liter class at five races with Ford Cortina Lotus winning twice.[1] Ford and Alfa Romeo won their respective class championships.[1]
Points were awarded according to finishing position.[1] Only the highest-placed car scored points for the manufacturer.[1] Drivers' championships were not awarded in Trans-Am until 1972.
The following models scored championship points for their respective manufacturers.