The 1966 World Sportscar Championship season was the 14th season of the FIA "World Sportscar Championship" motor racing. It featured the 1966 International Manufacturers' Championship and the 1966 International Sports Car Championship, which were contested between 5 February 1966 and September 11, 1966, over a total of thirteen races. The International Manufacturers' Championship was open to Group 6 Sports-Prototypes and was contested in two engine capacity divisions, P1 (Up to 2000cc) and P2 (Over 2000cc). The International Sports Car Championship was open to Group 4 Sports Cars and was contested in three engine capacity divisions, S1 (Up to 1300cc), S2 (1301 to 2000cc) and S3 (Over 2000cc).
The 13 championship races each counted towards one or more of the five divisions.
Both championships scored points to the top six competitors in each class, under four different tables or 'Baréme'. Baréme I corresponded with the old order of 9-6-4-3-2-1. Baréme II was in the order 10-7-5-4-3-2. Baréme III, valid only for Le Mans, was in the order 12-9-7-5-4-3. Baréme 0, valid only for the Grosser Bergpreis der Schweiz, was half of Baréme I: 4.5-3-2-1.5-1-0.5. Constructors were only awarded points for their highest finishing car. Other finishers from the same manufacturer were merely skipped in the points count.
Only the best 4 results counted towards the championship (5 in S3, 6 in S2). Points earned but not counted towards the championship total are listed in (brackets).
Note: The Hockenheim 500 km race did not count towards the Over 2000cc division of the International Manufacturers Championship.
The following models contributed to the nett points awarded to their respective manufacturers in the two championships.
International Manufacturers Championship - Over 2000cc
International Manufacturers Championship - Up to 2000cc
International Sports Car Championship - Division 1
International Sports Car Championship - Division 2
International Sports Car Championship - Division 3