| Dates | 4 May – 3 September 1966 |
|---|---|
| Administrator | England and Wales Cricket Board |
| Cricket format | First-class cricket |
| Tournament format | League system |
| Champions | Yorkshire (27th title) |
| Participants | 17 |
| Matches | 238 |
| Most runs | Tony Lewis, (Glamorgan) 1,960 |
| Most wickets | Derek Underwood, (Kent) 143 |
The 1966 County Championship was the 67th officially organised running of the County Championship. Yorkshire won the Championship title.
The method of obtaining points for the first innings was changed with two points awarded for a first innings lead for any match won, lost or drawn.
| Team | P | W | L | D | No Dec |
1st Inns Lead |
1st Inns Tie |
Pts | |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Yorkshire | 28 | 15 | 5 | 8 | 0 | 17 | 0 | 184 |
| 2 | Worcestershire | 28 | 13 | 5 | 9 | 1 | 18 | 0 | 166 |
| 3 | Somerset | 28 | 13 | 7 | 7 | 1 | 13 | 0 | 156 |
| 4 | Kent | 28 | 11 | 8 | 8 | 1 | 17 | 0 | 144 |
| 5 | Northamptonshire | 28 | 10 | 9 | 9 | 0 | 15 | 0 | 130 |
| 6 | Warwickshire | 28 | 8 | 8 | 10 | 2 | 16 | 1 | 113 |
| 7 | Surrey | 28 | 8 | 3 | 16 | 1 | 15 | 0 | 110 |
| 8 | Leicestershire | 28 | 8 | 7 | 12 | 1 | 14 | 0 | 108 |
| 9 | Derbyshire | 28 | 8 | 12 | 7 | 1 | 8 | 0 | 96 |
| 10 | Sussex | 28 | 6 | 11 | 11 | 0 | 16 | 0 | 92 |
| 11 | Hampshire | 28 | 5 | 4 | 18 | 1 | 15 | 0 | 87 |
| =12 | Lancashire | 28 | 6 | 11 | 8 | 3 | 13 | 0 | 86 |
| =12 | Middlesex | 28 | 6 | 5 | 14 | 3 | 13 | 0 | 86 |
| 14 | Glamorgan | 28 | 6 | 8 | 13 | 1 | 10 | 0 | 85 |
| 15 | Gloucestershire | 28 | 6 | 12 | 9 | 1 | 7 | 1 | 75 |
| 16 | Essex | 28 | 4 | 10 | 11 | 3 | 10 | 0 | 60 |
| 17 | Nottinghamshire | 28 | 3 | 11 | 12 | 2 | 8 | 0 | 46 |