The 2021 Spa-Francorchamps Formula 3 round was the fifth round of the 2021 FIA Formula 3 Championship.

It took place at the Circuit de Spa-Francorchamps and featured three races on the 28 August and 29 August in support of the 2021 Belgian Grand Prix.

With Jack Doohan winning both Sprint Race 2 and Feature Race respectively, it marked the first time in the series' history that a driver was able to win two races in a weekend.