Races in calendar week 21/2018
All motorsport events on the weekend of 25–27 May 2018.
| Circuit | Country | Series |
|---|---|---|
| Brownsburg (oval) |  USA |
|
| Charlotte (oval) | USA |
|
| Indianapolis (oval) | USA |
|
| Lakeville (Lime Rock) | USA |
|
| Monte Carlo |  Monaco |
|
| Snetterton |  Great Britain |
|
| Sugo |  Japan |
|