B
- (Mayo County) Brickeens
- (Roscommon) Breedoge
- (Mayo County) Breaghwy
- (County Galway) Brannock Islands
- (County Galway) Boston
- (Mayo County) Boghadoon
- (County Galway) Birmore Island
- (Mayo County) Belville
- (Sligo) Beltra
- (Mayo County) Beltra
- (County Galway) Belmont
- (Roscommon) Bellaugh
- (Roscommon) Bellanamullia
- (Mayo County) Bellanaboy Bridge
- (County Leitrim) Bellanaboy
- (Sligo) Bellahy
- (Mayo County) Bellacorick
- (Mayo County) Belderg
- (County Galway) Belclare
- (Mayo County) Bekan
- (County Galway) Bealadangan
- (Roscommon) Battle Bridge
- (Mayo County) Bartraw
- (Mayo County) Bartragh Island
- (Sligo) Barratogher
- (Mayo County) Barranagh Island
- (Mayo County) Barnycarroll
- (County Galway) Barnaderg
- (Mayo County) Barnacahoge
- (County Galway) Barna