The 1977 Formula One season was the 31st season of FIA Formula One motor racing. It featured the 28th World Championship of Drivers and the 20th International Cup for Formula 1 Constructors. The season commenced on 9 January 1977 and ended on 23 October after seventeen races, making it the longest Formula One season in the sport's history at the time. The season also included a single non-championship race for Formula One cars, the 1977 Race of Champions.

Niki Lauda won his second championship, despite Mario Andretti winning more races. Lauda did not complete the season, departing Scuderia Ferrari after securing the title at the 1977 United States Grand Prix. Ferrari won its third consecutive Constructors' title, with new driver Carlos Reutemann having a solid season.

The season was marred by a horrific accident during the South African GP: Tom Pryce was unable to avoid hitting 19-year-old race marshal Frederik Jansen van Vuuren, who had tried to cross the track. The latter was killed in the collision, while his fire extinguisher struck and killed Pryce. His car proceeded to the end of the straight where it collided with Jacques Laffite's Ligier. There was further tragedy as Carlos Pace lost his life in an aviation accident, only a couple of weeks later.

At the 1977 Japanese Grand Prix, the last race of the season, Gilles Villeneuve's second race driving for Ferrari ended in tragedy as well when, on lap 6 and, after colliding with Ronnie Peterson's six-wheel Tyrrell P34, his car became airborne and collided with track marshal Kengo Yuasa, who was trying to have trespassing spectators move away from a restricted area of the track. Villeneuve's car also hit photographer Kazuhiro Ohashi. Villeneuve's Ferrari was completely destroyed and, while he escaped uninjured, both Yuasa and Ohashi were killed instantly.

The following drivers and constructors contested the World Championship of Drivers and the International Cup for Formula 1 Constructors:

The 1977 season started in Argentina, returning after a year's absence. It was reigning world champion James Hunt who started off his title defence with pole position in his McLaren. Countryman John Watson shared the front row with him in the Brabham, and Patrick Depailler in the six-wheeled Tyrrell was third on the grid. The weather was, as was very often the case in Buenos Aires, oppressively hot, which contributed to the attrition of this race – the track temperature was 51 °C (124 °F).

Watson took the lead at the start with Hunt second. Watson led for the first 10 laps until Hunt moved ahead and pulled away, with Mario Andretti's Lotus third, but soon the other McLaren of Jochen Mass took the place. Mass had to retire soon after with an engine failure which caused him to spin, and a suspension failure took teammate and race leader Hunt out three laps later. Watson took the lead again, but he also had suspension failures and let teammate Carlos Pace through. Watson eventually retired, and Pace struggled towards the end due to heat in his cockpit and was passed by Jody Scheckter's Wolf and Andretti, but the latter retired then with a wheel bearing failure. Scheckter took the first win of 1977, with Pace second, and home hero Carlos Reutemann completing the podium for Ferrari.

The second round took place at the longest circuit of the year – the very demanding and difficult 5-mile Interlagos circuit in São Paulo, Brazil. Hunt took pole again with Reutemann second and Andretti third on the grid. Home hero Pace took the lead at the start, with Hunt dropping behind Reutemann as well but soon Hunt was back behind Pace and attacking. There was contact, and Hunt took the lead whereas Pace had to pit for repairs. Hunt led Reutemann until he began to suffer from tyre troubles and was passed by Reutemann. Hunt pitted for new tyres, and rejoined fourth and soon passed Niki Lauda in the Ferrari and Watson to reclaim second. Reutemann marched on to victory, Hunt was second and Lauda third after Watson crashed out.