| Country | Ireland England |
||
|---|---|---|---|
| Champions | Westmeath | ||
| Runner-up | London | ||
|
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The All-Ireland Senior B Hurling Championship of 1991 was the 18th staging of Ireland's secondary hurling knock-out competition. Westmeath won the championship, beating London 2-12 to 2-6 in the final at Cusack Park, Mullingar.