The 2021 REV Group Grand Prix at Road America was the ninth race of the 2021 IndyCar Series season.

Former F1 driver Kevin Magnussen, who would make his IndyCar debut, would replace Felix Rosenqvist, who suffered injuries at the 2021 Chevrolet Detroit Grand Prix.

[2][3] Oliver Askew would also replace an injured Rinus VeeKay, who suffered injuries in a cycling incident.

[4] In addition, NASCAR driver Cody Ware would make his IndyCar debut.

[8] The final practice session was held on Saturday, June 19, at 5:30 PM EST.

For round one, the field is divided into two groups based on the odd and even positions of drivers in the final pre-qualifying practice session.