| All-Ireland Senior B Hurling Championship | |
| Year: | 1984 |
| Country: | |
| Winners: | Westmeath |
| Second: | London |
| Prev Season: | 1983 |
| Next Season: | 1985 |
The 1984 All-Ireland Senior B Hurling Championship was the 11th staging of Ireland's secondary hurling knock-out competition. Westmeath won the centenary year championship, beating London 4–10 to 1–16 in the final at the Emerald GAA Grounds, Ruislip.