The 1903 County Championship served as the 14th edition of the competition. Fifteen teams participated in the tournament, which ran between 4 May and 3 September. Matches followed a first-class format lasting three days.
Middlesex secured their first championship title during this season. This victory ended a three-year streak of dominance by Yorkshire. Sussex claimed second place, marking the second year in a row the team finished as runners-up.
The competition operated on a league system. Points were awarded with one for a win and a deduction of one for every loss. Officials determined final rankings by dividing the points earned by the total number of completed matches and multiplying the result by 100.
C. B. Fry recorded the most runs across the season, finishing with 2,413 for Sussex. Wilfred Rhodes led the bowling charts, taking 143 wickets for Yorkshire.
| Team | Pld | W | L | D | A | Pts | Fin | %Fin |
| Middlesex | 18 | 8 | 1 | 7 | 2 | 7 | 9 | 77.77 |
| Sussex | 24 | 7 | 2 | 14 | 1 | 5 | 9 | 55.55 |
| Yorkshire | 26 | 13 | 5 | 8 | 0 | 8 | 18 | 44.44 |
| Lancashire | 26 | 10 | 5 | 11 | 0 | 3 | 15 | 33.33 |
| Nottinghamshire | 20 | 6 | 4 | 10 | 0 | 2 | 10 | 20.00 |
| Worcestershire | 20 | 8 | 6 | 6 | 0 | 2 | 14 | 14.28 |
| Warwickshire | 18 | 5 | 4 | 9 | 0 | 1 | 9 | 11.11 |
| Essex | 22 | 7 | 6 | 7 | 2 | 1 | 13 | 7.69 |
| Kent | 22 | 7 | 6 | 7 | 2 | 1 | 13 | 7.69 |
| Somerset | 18 | 6 | 6 | 5 | 1 | 0 | 12 | 0.00 |
| Surrey | 28 | 7 | 11 | 9 | 1 | –4 | 18 | –22.22 |
| Derbyshire | 16 | 4 | 7 | 5 | 0 | –3 | 11 | –27.27 |
| Gloucestershire | 20 | 3 | 10 | 7 | 0 | –7 | 13 | –53.84 |
| Hampshire | 18 | 1 | 10 | 4 | 3 | –9 | 11 | –81.81 |
| Leicestershire | 18 | 1 | 10 | 4 | 3 | –9 | 11 | –81.81 |
| Source: |
Squad lists and statistics via Wikipedia