The Tatuus F4-T421 is an open-wheel formula race car, designed, developed and built by Italian manufacturer Tatuus, for Formula 4 junior categories, since 2021.[1] [2] [3] [4]
In January 2021, it was first announced that the car would go into production to make its competitive debut in the 2022 Formula 4 UAE Championship, as the successor of the Tatuus F4-T014, featuring the introduction of the halo, and other improved safety features.[5] Over the course of 2021, many Formula 4 championships announced their intent to use the car in the 2022 season: the Italian F4 Championship,[6] F4 British Championship,[7] F4 Spanish Championship, Formula 4 UAE Championship, F4 Brazilian Championship, ACCR Formula 4 Championship and ADAC Formula 4.
The car first began testing in September 2021.[8] The car made its competition debut in the 2022 Formula 4 UAE Championship, and featured in the 2022 seasons of all announced championships excluding the ACCR Formula 4 Championship, which was postponed due to global supply chain issues.[9]
| Year introduced | Country | Championship | Season introduced |
|---|---|---|---|
| 2022 |  Italy | Italian F4 Championship | 2022 |
| Germany | ADAC Formula 4 | 2022 | |
 Spain | F4 Spanish Championship | 2022 | |
 United Kingdom | F4 British Championship | 2022 | |
| United Arab Emirates | F4 UAE Championship | 2022 | |
 Brazil | 2022 | ||
| 2023 |  Austria Czech Republic Hungary Slovakia | Formula 4 CEZ Championship | 2023 |
| Spain | Formula Winter Series | 2023 | |
| International | F1 Academy | 2023 | |
 ChinaMalaysia | Formula 4 South East Asia Championship | 2023 | |
| 2024 |  Saudi Arabia | F4 Saudi Arabian Championship | 2024 |
 Australia | Formula 4 Australian Championship | 2024 | |
 | NACAM Formula 4 Championship | 2024 | |