Variant spellings are included, so there may be some duplication. If you know of something that should be included, please let me know
| Bagley |
| Bailey |
| Bailie |
| Báille |
| Baillie |
| Bailly |
| Baily |
| Bairéid |
| Bairéid Ardrahan, Co. Galway |
| Bairéid (archived) |
| Bairéid (archived) |
| Bairéid Belmullet, Co. Mayo |
| Baley |
| Bamfield |
| Banfield |
| Barber Sligo |
| Barbor Sligo |
| Barbour Sligo |
| Barden (archived) |
| Bardin (archived) |
| Bardon (archived) |
| Barett |
| Barett Ardrahan, Co. Galway |
| Barett (archived) |
| Barett (archived) |
| Barett Belmullet, Co. Mayo |
| Barette |
| Barette Ardrahan, Co. Galway |
| Barette (archived) |
| Barette (archived) |
| Barette Belmullet, Co. Mayo |
| Bargary |
| Baróid |
| Baróid Ardrahan, Co. Galway |
| Baróid (archived) |
| Baróid (archived) |
| Baróid Belmullet, Co. Mayo |
| Barragry |
| Barret |
| Barret Ardrahan, Co. Galway |
| Barret (archived) |
| Barret (archived) |
| Barret Belmullet, Co. Mayo |
| Barrett |
| Barrett Ardrahan, Co. Galway |
| Barrett (archived) |
| Barrett (archived) |
| Barrett Belmullet, Co. Mayo |
| Barrott |
| Barrott Ardrahan, Co. Galway |
| Barrott (archived) |
| Barrott (archived) |
| Barrott Belmullet, Co. Mayo |
| Baylee |
| Bayley |
| Baylie |
| Bayly |
| Beagan |
| Beagin |
| Beagon |
| Beattey |
| Beattey |
| Beattie |
| Beattie |
| Beatty |
| Beatty |
| Beaty |
| Beaty |
| Beck Mullaghbrack, Co. Armagh |
| Beegan |
| Began |
| Begley |
| Begly |
| Beirne Byrne clan |
| Beirne |
| Beirne |
| Beirne |
| Beirnes Byrne clan |
| Beirnes |
| Beirnes |
| Beirnes |
| Bell |
| Beracree |
| Berecree |
| Beregra |
| Bergan |
| Bergin |
| Berkary |
| Berkerry |
| Berkery |
| Berne Byrne clan |
| Berne |
| Berne |
| Berne |
| Berrecry |
| Berrie |
| Berry |
| Bertridge Carrick-on-Shannon, Co. Leitrim |
| Biadhtach |
| Biadhtach |
| Bigley |
| Biracry |
| Birkerry |
| Birne |
| Blackburn Armagh |
| Blackburne Armagh |
| Blain |
| Blaine |
| Blane |
| Blaney Co. Westmeath, Quebec |
| Blany Co. Westmeath, Quebec |
| Blayne |
| Blayney Co. Westmeath, Quebec |
| Blean |
| Bleany Co. Westmeath, Quebec |
| Bléine Co. Westmeath, Quebec |
| Boales Co. Clare |
| Boales Co. Tyrone |
| Boales |
| Boales Belfast, South Carolina |
| Boden Co. Down |
| Bódún Co. Down |
| Bohan (archived) |
| Bohane (archived) |
| Bohen (archived) |
| Bohun (archived) |
| Boid |
| Boid (archived) |
| Bóidín Co. Down |
| Boil |
| Boil Co. Clare |
| Boil Co. Tyrone |
| Boil |
| Boil Belfast, South Carolina |
| Boile |
| Boile Co. Clare |
| Boile Co. Tyrone |
| Boile |
| Boile Belfast, South Carolina |
| Bolan (archived) |
| Boland (archived) |
| Bolds Co. Clare |
| Bolds Co. Tyrone |
| Bolds |
| Bolds Belfast, South Carolina |
| Bole Co. Clare |
| Bole Co. Tyrone |
| Bole |
| Bole Belfast, South Carolina |
| Boles Co. Clare |
| Boles Co. Tyrone |
| Boles |
| Boles Belfast, South Carolina |
| Boohan (archived) |
| Boohane (archived) |
| Boohin (archived) |
| Boughan (archived) |
| Boughen (archived) |
| Bourk |
| Bourk Skibbereen, Co. Cork. |
| Bourk |
| Bourk (archived) |
| Bourk Tipperary |
| Bourk Glenamaddy, Co. Galway |
| Bourk |
| Bourke |
| Bourke Skibbereen, Co. Cork. |
| Bourke |
| Bourke (archived) |
| Bourke Tipperary |
| Bourke Glenamaddy, Co. Galway |
| Bourke |
| Bourn |
| Bourn (archived) |
| Bourn |
| Bourn |
| Bourn Clan O'Byrne |
| Bourn Kilcar, Co. Donegal/Nevada |
| Bourne |
| Bourne (archived) |
| Bourne |
| Bourne |
| Bourne Clan O'Byrne |
| Bourne Kilcar, Co. Donegal/Nevada |
| Bournes |
| Bourns |
| Bowden Co. Down |
| Boyan (archived) |
| Boyd |
| Boyd (archived) |
| Boyde |
| Boyde (archived) |
| Boyee |
| Boyee (archived) |
| Boyhan (archived) |
| Boyle |
| Boyle Co. Clare |
| Boyle Co. Tyrone |
| Boyle |
| Boyle Belfast, South Carolina |
| Brady Cavan |
| Brady |
| Branan Kilkenny |
| Branan Galway /Dakota county, Minn |
| Branan Idough & Canada (archived) |
| Branan (archived) |
| Branan Laois & Carlow |
| Branan Ulster |
| Branan Startford, Ontario and Michigan |
| Branan Connacht |
| Branan |
| Brannan Kilkenny |
| Brannan Galway /Dakota county, Minn |
| Brannan Idough & Canada (archived) |
| Brannan (archived) |
| Brannan Laois & Carlow |
| Brannan Ulster |
| Brannan Startford, Ontario and Michigan |
| Brannan Connacht |
| Brannan |
| Brannen Kilkenny |
| Brannen Galway /Dakota county, Minn |
| Brannen Idough & Canada (archived) |
| Brannen (archived) |
| Brannen Laois & Carlow |
| Brannen Ulster |
| Brannen Startford, Ontario and Michigan |
| Brannen Connacht |
| Brannen |
| Brannon Kilkenny |
| Brannon Galway /Dakota county, Minn |
| Brannon Idough & Canada (archived) |
| Brannon (archived) |
| Brannon Laois & Carlow |
| Brannon Ulster |
| Brannon Startford, Ontario and Michigan |
| Brannon Connacht |
| Brannon |
| Brasil |
| Brasil |
| Brassel |
| Brassel |
| Brassell |
| Brassell |
| Brassil |
| Brassil |
| Brassill |
| Brassill |
| Braton |
| Braton |
| Brattan |
| Brattan |
| Bratten |
| Bratten |
| Brattin |
| Brattin |
| Bratton |
| Bratton |
| Brazel |
| Brazel |
| Brazell |
| Brazell |
| Brazil |
| Brazil |
| Brazill |
| Brazill |
| Brazzil |
| Brazzil |
| Brazzill |
| Brazzill |
| Bready Cavan |
| Bready |
| Breathnach |
| Breathnach |
| Breathnach Kilkenny/Iowa |
| Breathnach Kiltimagh, Co. Mayo |
| Breathnach Kilkenny/Nebraska |
| Breatnach |
| Breatnach |
| Breatnach Kilkenny/Iowa |
| Breatnach Kiltimagh, Co. Mayo |
| Breatnach Kilkenny/Nebraska |
| Breen Australia |
| Breen (archived) |
| Breen |
| Breen |
| Breene Australia |
| Breene (archived) |
| Breene |
| Breene |
| Brenan Kilkenny |
| Brenan Galway /Dakota county, Minn |
| Brenan Idough & Canada (archived) |
| Brenan (archived) |
| Brenan Laois & Carlow |
| Brenan Ulster |
| Brenan Startford, Ontario and Michigan |
| Brenan Connacht |
| Brenan |
| Brennan Kilkenny |
| Brennan Galway /Dakota county, Minn |
| Brennan Idough & Canada (archived) |
| Brennan (archived) |
| Brennan Laois & Carlow |
| Brennan Ulster |
| Brennan Startford, Ontario and Michigan |
| Brennan Connacht |
| Brennan |
| Brennon Kilkenny |
| Brennon Galway /Dakota county, Minn |
| Brennon Idough & Canada (archived) |
| Brennon (archived) |
| Brennon Laois & Carlow |
| Brennon Ulster |
| Brennon Startford, Ontario and Michigan |
| Brennon Connacht |
| Brennon |
| Breslan |
| Bresland |
| Breslane |
| Breslin |
| Brew |
| Brian Australia |
| Brian (archived) |
| Brian |
| Brian |
| Brien Australia |
| Brien (archived) |
| Brien |
| Brien |
| Briens Australia |
| Briens (archived) |
| Briens |
| Briens |
| Brindley |
| Brindly |
| Brine Australia |
| Brine (archived) |
| Brine |
| Brine |
| Brislan |
| Brisland |
| Brislane |
| Brislaun |
| Brislin |
| Broe |
| Brown |
| Browne |
| Brundley |
| Brusland |
| Bryan Australia |
| Bryan (archived) |
| Bryan |
| Bryan |
| Bryans Australia |
| Bryans (archived) |
| Bryans |
| Bryans |
| Bryne Australia |
| Bryne (archived) |
| Bryne |
| Bryne |
| Buhen (archived) |
| Buhin (archived) |
| Burgh |
| Burgh Skibbereen, Co. Cork. |
| Burgh |
| Burgh (archived) |
| Burgh Tipperary |
| Burgh Glenamaddy, Co. Galway |
| Burgh |
| Burke Skibbereen, Co. Cork. |
| Burke |
| Burke (archived) |
| Burke Tipperary |
| Burke Glenamaddy, Co. Galway |
| Burn |
| Burn (archived) |
| Burn |
| Burn |
| Burn Clan O'Byrne |
| Burn Kilcar, Co. Donegal/Nevada |
| Burne |
| Burne (archived) |
| Burne |
| Burne |
| Burne Clan O'Byrne |
| Burne Kilcar, Co. Donegal/Nevada |
| Burnes |
| Burns |
| Butler |
| Butler New Ross, Galway and La Rochelle |
| Byrne |
| Byrne (archived) |
| Byrne |
| Byrne |
| Byrne Clan O'Byrne |
| Byrne Kilcar, Co. Donegal/Nevada |
| Byrnes |
| Byrns |