| Type R3: | Feature race |
| Type R1: | Sprint race 1 |
| Type R2: | Sprint race 2 |
| Monza | |
| Round No: | 5 |
| Season No: | 8 |
| Year: | 2021 |
| Country: | Italy |
| Location: | Autodromo Nazionale di Monza, Monza, Italy |
| Course: | Permanent Circuit |
| Course Mi: | 3.600 |
| Course Km: | 5.793 |
| Date R1: | 11 September |
| Laps R1: | 21 |
| First Driver Country R1: | FRA |
| First Driver R1: | Théo Pourchaire |
| First Team R1: | ART Grand Prix |
| Second Driver Country R1: | PRC |
| Second Driver R1: | Guanyu Zhou |
| Second Team R1: | UNI-Virtuosi |
| Third Driver Country R1: | DNK |
| Third Driver R1: | Christian Lundgaard |
| Third Team R1: | ART Grand Prix |
| Fast Driver Country R1: | FRA |
| Fast Driver R1: | Théo Pourchaire |
| Fast Team R1: | ART Grand Prix |
| Fast Time R1: | 1:34.314 |
| Fast Lap R1: | lap 16 |
| Date R2: | 11 September |
| Laps R2: | 21 |
| First Driver Country R2: | IND |
| First Driver R2: | Jehan Daruvala |
| First Team R2: | Carlin |
| Second Driver Country R2: | NED |
| Second Driver R2: | Bent Viscaal |
| Second Team R2: | Trident |
| Third Driver Country R2: | RUS |
| Third Driver R2: | Robert Shwartzman |
| Third Team R2: | Prema Racing |
| Fast Driver Country R2: | AUS |
| Fast Driver R2: | Oscar Piastri |
| Fast Team R2: | Prema Racing |
| Fast Time R2: | 1:35.239 |
| Fast Lap R2: | lap 6 |
| Date R3: | 12 September |
| Laps R3: | 30 |
| Pole Driver Country R3: | AUS |
| Pole Driver R3: | Oscar Piastri |
| Pole Team R3: | Prema Racing |
| Pole Time R3: | 1:32.199 |
| First Driver Country R3: | AUS |
| First Driver R3: | Oscar Piastri |
| First Team R3: | Prema Racing |
| Second Driver Country R3: | PRC |
| Second Driver R3: | Guanyu Zhou |
| Second Team R3: | UNI-Virtuosi Racing |
| Third Driver Country R3: | GBR |
| Third Driver R3: | Dan Ticktum |
| Third Team R3: | Carlin |
| Fast Driver Country R3: | NZL |
| Fast Driver R3: | Liam Lawson |
| Fast Team R3: | Hitech Grand Prix |
| Fast Time R3: | 1:35.000 |
| Fast Lap R3: | lap 14 |
The 2021 Monza Formula 2 round was the fifth round of the 2021 Formula 2 Championship and took place at the Monza Circuit from 10 to 12 September. It ran in support of the 2021 Italian Grand Prix and featured three races.