Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Blairsville | Populated Place | 122 | Williamson | 37 48 40 N | 089 07 25 W |
| Blaisdell Hall | Building | 229 | Champaign | 40 06 01 N | 088 13 10 W |
| Blake School (historical) | School | 178 | Christian | 39 42 50 N | 089 20 46 W |
| Blake School (historical) | School | 240 | Ford | 40 27 58 N | 088 01 21 W |
| Blake School (historical) | School | 267 | Winnebago | 42 22 20 N | 089 22 45 W |
| Blakemans Ford | Crossing | 174 | Coles | 39 27 25 N | 088 08 50 W |
| Blakes | Populated Place | 186 | La Salle | 41 27 31 N | 088 45 10 W |
| Blakeslee Cemetery | Cemetery | 205 | Knox | 40 44 27 N | 090 06 00 W |
| Blalock Creek | Stream | | Woodford | 40 50 57 N | 089 30 21 W |
| Blanchard Chute | Stream | | Rock Island | 41 19 25 N | 091 03 57 W |
| Blanchard Hall | Building | 238 | DuPage | 41 52 07 N | 088 05 58 W |
| Blanchard Island | Island | 165 | Rock Island | 41 21 17 N | 091 03 45 W |
| Blanchard Island Recreation Area | Park | 165 | Rock Island | 41 20 53 N | 091 03 21 W |
| Blanchard Road Alliance Church | Church | 229 | DuPage | 41 50 15 N | 088 06 00 W |
| Blanchard School (historical) | School | 224 | Ford | 40 25 09 N | 088 05 54 W |
| Blanchard School (historical) | School | 196 | Lake | 42 23 58 N | 087 49 44 W |
| Blanchard School (historical) | School | 238 | Stephenson | 42 15 32 N | 089 31 57 W |
| Blanche and Frank L Seaver Physical Education Building | Building | 258 | Winnebago | 42 16 07 N | 089 00 57 W |
| Blanche Walker Burpee Center | Building | 259 | Winnebago | 42 16 11 N | 089 01 07 W |
| Bland Landing Strip | Airport | 201 | Moultrie | 39 37 50 N | 088 44 45 W |
| Blanding | Populated Place | 200 | Jo Daviess | 42 16 29 N | 090 23 09 W |
| Blanding Landing Recreation Area | Locale | 184 | Jo Daviess | 42 17 09 N | 090 24 12 W |
| Blandinsville | Populated Place | 222 | McDonough | 40 33 22 N | 090 51 57 W |
| Blandinsville City Lake Dam | Dam | 220 | McDonough | 40 33 48 N | 090 52 00 W |
| Blandinsville City Reservoir | Reservoir | 220 | McDonough | 40 33 48 N | 090 52 00 W |
| Blandinsville School (historical) | School | 220 | McDonough | 40 33 17 N | 090 52 06 W |
| Blandinsville United Methodist Church | Church | 221 | McDonough | 40 33 20 N | 090 52 06 W |
| Blandinsville-Hire Community Center | Building | 220 | McDonough | 40 33 17 N | 090 52 06 W |
| Blanke Lake | Lake | 127 | Clinton | 38 34 00 N | 089 22 57 W |
| Blankenship Cemetery | Cemetery | 165 | Fayette | 39 08 34 N | 088 58 21 W |