The following is an overview of the events of 2003 in motorsport including the major racing events, motorsport venues that were opened and closed during a year, championships and non-championship events that were established and disestablished in a year, and births and deaths of racing drivers and other motorsport people.
The calendar includes only annual major non-championship events or annual events that had significance separate from the championship. For the dates of the championship events see related season articles.
| Date | Event | Ref | 
|---|---|---|
| 1–19 January | 25th Dakar Rally | [1] | 
| 1–2 February | 41st 24 Hours of Daytona | [2] | 
| 16 February | 45th Daytona 500 | [3] | 
| 25 May | 87th Indianapolis 500 | [4] | 
| 31 May-1 June | 31st 24 Hours of Nurburgring | [5] | 
| 1 June | 61st Monaco Grand Prix | [6] | 
| 24 May-7 June | 85th Isle of Man TT | [7] | 
| 14–15 June | 71st 24 Hours of Le Mans | [8] | 
| 26–27 July | 55th 24 Hours of Spa | [9] | 
| 3 August | 26th Suzuka 8 Hours | [10] | 
| 10 August | 13th Masters of Formula 3 | [11] | 
| 12 October | 46th Bob Jane T-Marts 1000 | [12] | 
| 16 November | 50th Macau Grand Prix | [13] | 
| 29–30 November | 16th Race of Champions | [14] | 
| Date | Month | Name | Age | Nationality | Occupation | Note | Ref | 
|---|---|---|---|---|---|---|---|
| 10 | March | Barry Sheene | 52 | British | Motorcycle racer | 500cc Grand Prix motorcycle racing World champion (1976-1977). | [15] | 
| 6 | April | Daijiro Kato | 26 | Japanese | Motorcycle racer | 250cc Grand Prix motorcycle racing World champion (2001) |