The 1978 British Formula Three season was the 28th season of the British Formula Three racing. There was once again two major championships contested throughout the year: the British Automobile Racing Club organised BP Super Visco British Formula 3 Championship, and the British Racing Drivers' Club backed Vandervell British Formula 3 Championship. This would be the final year with multiple British championship, with the BARC and BRDC unifying for the following season.
The BARC championship was won by Brazilian driver Nelson Piquet ahead of British driver Derek Warwick, whilst in the BRDC championship, Warwick triumphed over Piquet.[1] Piquet subsequently moved up into Formula One during the same year, driving for the Brabham team in the final Formula 1 race of the season as well as two other teams earlier.