1991 All-Ireland Senior B Hurling Championship
| Dates | 12 May – 7 July 1991 | ||
|---|---|---|---|
| Teams | 10 | ||
| Champions | Westmeath (3rd title) Pat O'Brien (captain) Joachim Kelly (manager) | ||
| Runners-up | London | ||
| Tournament statistics | |||
| Matches played | 10 | ||
| Goals scored | 40 (4 per match) | ||
| Points scored | 215 (21.5 per match) | ||
| Top scorer(s) | David Kilcoyne (2-19) | ||
| |||
The 1991 All-Ireland Senior B Hurling Championship was the 18th staging of the All-Ireland Senior B Hurling Championship since its establishment by the Gaelic Athletic Association in 1974. The championship ran from 12 May to 7 July 1991.
London entered the championship as the defending champions.
The All-Ireland final was played at Cusack Park in Mullingar on 7 July 1991 between Westmeath and London, in what was their third meeting in the All-Ireland final and a first meeting in seven years. Westmeath won the match by 2-12 to 2-06 to claim their third All-Ireland title overall.
Westmeath's David Kilcoyne was the championship's top scorer with 2-19.