| Administrator(s) | Test and County Cricket Board |
|---|---|
| Cricket format | Limited overs cricket(40 overs per innings) |
| Tournament format(s) | League |
| Champions | Lancashire (3rd title) |
| Participants | 17 |
| Matches | 136 |
| Most runs | 691 Alec Stewart (Surrey) |
| Most wickets | 29 Kevin Saxelby (Nottinghamshire) |
The 1989 Refuge Assurance League was the twenty-first competing of what was generally known as the Sunday League. The competition was won for the third time by Lancashire County Cricket Club.