Places beginning with BO in Illinois, United States
- Boaz
- Bobtown
- Boden
- Bodmann
- Bogota
- Bohemian California (subdivision)
- Bohleysville
- Bois d'Arc, Township of
- Bolingbrook
- Bolivia
- Bolo, Township of
- Bolton
- Bond County
- Bond, Township of
- Bondville
- Bone Gap
- Bone Gap Election Precinct
- Bonfield
- Bongard
- Bonnie
- Bonnie Valley
- Bonpas, Township of
- Bonus, Township of
- Boody
- Boone County
- Boone, Township of
- Boos
- Boothby
- Borton
- Boschome (subdivision)
- Boskydell
- Boulder
- Boulder Hill
- Bourbon
- Bourbonais (historical)
- Bourbonnais
- Bourbonnais, Township of
- Bourbon, Township of
- Bowdre, Township of
- Bowen
- Bowes
- Bowes Bend
- Bowlesville (historical)
- Bowlesville, Township of
- Bowling Green (historical)
- Bowling Green, Township of
- Bowling, Township of
- Bowman (historical)
- Bowmanville (subdivision)
- Boyd
- Boyle
- Boyleston
- Boynton
- Boynton, Township of