| Administrator: | Test and County Cricket Board |
| Cricket Format: | Limited overs cricket(40 overs per innings) |
| Tournament Format: | League |
| Champions: | Essex |
| Count: | 1 |
| Participants: | 17 |
| Matches: | 136 |
| Most Runs: | 618 John Wright (Derbyshire) |
| Most Wickets: | 33 Anton Ferreira (Warwickshire) |
| Previous Year: | 1980 |
| Previous Tournament: | 1980 John Player League |
| Next Year: | 1982 |
| Next Tournament: | 1982 John Player League |
The 1981 John Player League was the thirteenth competing of what was generally known as the Sunday League. The competition was won for the first time by Essex County Cricket Club.
| width=200 | Team | width=20 | Pld | width=20 | W | width=20 | T | width=20 | L | width=20 | N/R | width=20 | A | width=20 | Pts | width=60 | R/R |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Essex (C) | 16 | 12 | 0 | 3 | 1 | 0 | 50 | 4.888 | |||||||||
| 16 | 11 | 0 | 5 | 0 | 0 | 44 | 4.949 | ||||||||||
| 16 | 10 | 0 | 4 | 0 | 2 | 44 | 5.351 | ||||||||||
| 16 | 10 | 0 | 5 | 0 | 1 | 42 | 4.571 | ||||||||||
| 16 | 8 | 0 | 5 | 0 | 3 | 38 | 5.189 | ||||||||||
| 16 | 8 | 0 | 7 | 0 | 1 | 34 | 4.952 | ||||||||||
| 16 | 7 | 1 | 7 | 1 | 0 | 32 | 4.480 | ||||||||||
| 16 | 7 | 0 | 7 | 1 | 1 | 32 | 4.552 | ||||||||||
| 16 | 6 | 0 | 6 | 2 | 2 | 32 | 4.757 | ||||||||||
| 16 | 6 | 0 | 8 | 2 | 0 | 28 | 4.287 | ||||||||||
| 16 | 6 | 1 | 8 | 1 | 0 | 28 | 4.422 | ||||||||||
| 16 | 6 | 0 | 8 | 0 | 2 | 28 | 4.452 | ||||||||||
| 16 | 7 | 0 | 9 | 0 | 0 | 28 | 4.770 | ||||||||||
| 16 | 5 | 0 | 9 | 0 | 2 | 24 | 4.346 | ||||||||||
| 16 | 4 | 0 | 9 | 1 | 2 | 22 | 4.862 | ||||||||||
| 16 | 3 | 0 | 9 | 3 | 1 | 20 | 4.904 | ||||||||||
| 16 | 4 | 0 | 11 | 0 | 1 | 18 | 4.745 | ||||||||||
| Team marked | |||||||||||||||||