Places beginning with BA in Illinois, United States
- Babcock
- Babylon
- Back of the Yards (subdivision)
- Bader
- Bailey Falls (historical)
- Baileyville
- Bainbridge
- Bainbridge, Township of
- Baker
- Bakers Acres
- Bakers Crossroads
- Bakerville
- Bakerville
- Balcom
- Balcom Election Precinct
- Bald Bluff
- Bald Bluff, Township of
- Bald Hill, Township of
- Bald Mound
- Baldwin
- Baldwin Beach
- Baldwin Election Precinct
- Baldwin Heights
- Baldwin (subdivision)
- Ballou
- Ball, Township of
- Bancroft Corners
- Bando
- Banklick
- Banner
- Banner, Township of
- Banner, Township of
- Bannister
- Bannockburn
- Barbers Corners
- Barclay
- Bardolph
- Barlow Park
- Barnard Mill (historical)
- Barnes
- Barnett
- Barnett
- Barnett, Township of
- Barnhill
- Barnhill, Township of
- Barr
- Barr
- Barren, Township of
- Barreville
- Barrington
- Barrington Center
- Barrington Hills
- Barrington Hills
- Barrington, Township of
- Barrington Woods
- Barrow
- Barr, Township of
- Barry
- Barry, Township of
- Barstow
- Bartelso
- Bartlett
- Bartonville
- Basco
- Batavia
- Batavia Junction
- Batavia, Township of
- Batchtown
- Bates
- Batestown
- Bath
- Bath, Township of
- Baum
- Bay City
- Bayle City
- Baylestown
- Baylis
- Bay View Garden