The 1921 County Championship marked the 32nd edition of the tournament. Seventeen teams competed in this first-class league system held in England. The structure relied on a percentage of possible points to determine the final rankings, which made every match significant for the overall standings.
Points were awarded based on specific performance criteria. A win earned a team five points. If a match ended in a draw, the side that secured a first-innings lead received two points. This system encouraged teams to push for results rather than settling for a stalemate.
Middlesex finished the season as the champions. This victory represented the third title in the history of the club. They managed to navigate the format effectively to secure the top spot among the seventeen participating teams.
| Team | Pld | W | L | DWF | DLF | NR | Pts | %PC |
| Middlesex | 20 | 15 | 2 | 0 | 2 | 1 | 75 | 78.94 |
| Surrey | 24 | 15 | 2 | 3 | 3 | 1 | 81 | 70.43 |
| Yorkshire | 26 | 16 | 3 | 4 | 2 | 1 | 88 | 70.40 |
| Kent | 26 | 16 | 7 | 2 | 1 | 0 | 84 | 64.61 |
| Lancashire | 28 | 15 | 4 | 4 | 3 | 2 | 83 | 63.84 |
| Hampshire | 28 | 14 | 9 | 4 | 1 | 0 | 78 | 55.71 |
| Gloucestershire | 24 | 12 | 12 | 0 | 0 | 0 | 60 | 50.00 |
| Nottinghamshire | 24 | 10 | 8 | 3 | 2 | 1 | 56 | 48.69 |
| Sussex | 28 | 13 | 12 | 1 | 2 | 0 | 67 | 47.85 |
| Somerset | 22 | 8 | 11 | 2 | 1 | 0 | 44 | 40.00 |
| Leicestershire | 26 | 10 | 14 | 0 | 2 | 0 | 50 | 38.46 |
| Derbyshire | 20 | 5 | 12 | 3 | 0 | 0 | 31 | 31.00 |
| Northamptonshire | 24 | 5 | 15 | 1 | 2 | 1 | 27 | 23.47 |
| Worcestershire | 22 | 5 | 15 | 0 | 2 | 0 | 25 | 22.72 |
| Essex | 26 | 5 | 13 | 2 | 6 | 0 | 29 | 22.30 |
| Warwickshire | 26 | 5 | 18 | 1 | 2 | 0 | 27 | 20.76 |
| Glamorgan | 18 | 2 | 14 | 1 | 0 | 1 | 12 | 14.11 |
Squad lists and statistics via Wikipedia