The field arrived in Canada without
Niki Lauda who, having clinched the Drivers' Championship at the previous race at
Watkins Glen, and having already announced his intention to drive for
Brabham in , abruptly quit
Ferrari upon learning that the team would bet on the
312T3 model, more conservative, but still technically more outdated in relation to cars with ground effect (which was becoming popular in the category thanks to the success of the
Lotus 78).
Canadian driver
Gilles Villeneuve who had made a one-off appearance for McLaren earlier in the season at the
British Grand Prix took Lauda's place in the Ferrari team. In qualifying,
Lotus's
Mario Andretti took his sixth pole position of the season, with
McLaren's
James Hunt alongside him on the front row.
Ronnie Peterson was third in his six-wheeled
Tyrrell, ahead of
Gunnar Nilsson in the second Lotus. The top ten was completed by
Jochen Mass in the second McLaren,
Patrick Depailler in the second Tyrrell, the
Shadows of
Alan Jones and
Riccardo Patrese,
Jody Scheckter in the
Wolf, and
John Watson in the Brabham. But the safety of the bumpy, high-speed Mosport Park track was in question: during practice
Ian Ashley's
Hesketh crested one of these bumps on the Mario Andretti straight; it flipped, vaulted the barrier and crashed into a television tower, seriously injuring Ashley and ending his Formula One career. The Englishman survived, but it took 40 minutes to remove him from the car and an additional 30 minutes passed until a helicopter arrived. These problems were underlined later that day when Mass crashed at the first corner into a barrier that flattened upon impact. At the start of the race, Andretti led away from Hunt, with Mass charging up to third. Andretti and Hunt then proceeded to pull away from the rest of the field, such that by three-quarter distance, they were coming up to lap third-placed Mass. As they did so, Hunt pulled ahead of Andretti, only to collide with his McLaren team-mate after a misunderstanding. Unable to continue, a visibly furious and agitated Hunt waved his fist at Mass, before punching a marshal and immediately then apologize who was trying to usher him away. He was subsequently fined $2000 for assaulting a marshal and $750 for walking back to the pit lane in an "unsafe manner". Andretti's retirement meant that Scheckter inherited the win, with Depailler second and the recovered Mass completing the podium. Jones was fourth ahead of
Patrick Tambay in the
Ensign, while Brambilla was classified sixth, just ahead of Ongais. This was the last Formula One race at Mosport Park. Although reasonably popular with drivers and fans, there was criticism that the track was cracked due to the cold Canadian forest weather later in the year (when the race was originally held) and that the drainage was poor, putting the safety of the drivers at risk, and so the
Canadian Grand Prix was moved to the
Circuit Gilles Villeneuve on
Notre Dame Island in
Montreal from
1978 onwards, where it has remained ever since. ==Classification==