Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Forest Lawn Cemetery | Cemetery | 211 | McDonough | 40 27 09 N | 090 43 09 W |
| Forest Lawn Memorial Gardens | Cemetery | 201 | Adams | 39 55 53 N | 091 21 10 W |
| Forest Lawn Memorial Park | Cemetery | 175 | La Salle | 41 20 29 N | 089 03 17 W |
| Forest Oak School (historical) | School | 200 | Greene | 39 14 43 N | 090 30 11 W |
| Forest Park | Park | 188 | Cook | 41 52 23 N | 087 48 43 W |
| Forest Park | Park | 193 | Iroquois | 40 46 33 N | 087 44 29 W |
| Forest Park | Park | 203 | Lake | 42 15 11 N | 087 49 16 W |
| Forest Park | Park | 248 | McLean | 40 27 40 N | 089 00 23 W |
| Forest Park | Park | 173 | Sangamon | 39 45 38 N | 089 35 21 W |
| Forest Park | Park | 194 | Shelby | 39 25 20 N | 088 47 14 W |
| Forest Park | Park | 195 | Will | 41 33 07 N | 088 03 05 W |
| Forest Park | Populated Place | 190 | Cook | 41 52 46 N | 087 48 49 W |
| Forest Park | Populated Place | 188 | Will | 41 32 45 N | 088 03 23 W |
| Forest Park Baptist Church | Church | 190 | Cook | 41 53 02 N | 087 48 19 W |
| Forest Park Cemetery | Cemetery | 199 | Vermilion | 39 58 29 N | 087 37 28 W |
| Forest Park Early Childhood Center | School | 188 | Cook | 41 51 27 N | 087 47 20 W |
| Forest Park Individual Education School | School | 195 | Will | 41 32 53 N | 088 03 18 W |
| Forest Park Mall Shopping Center | Locale | 189 | Cook | 41 51 47 N | 087 48 50 W |
| Forest Park Middle School | School | 189 | Cook | 41 52 10 N | 087 48 36 W |
| Forest Park Nature Center | Park | 209 | Peoria | 40 45 23 N | 089 34 45 W |
| Forest Park Nature Preserve | Park | | Peoria | 40 45 47 N | 089 34 54 W |
| Forest Park Post Office | Post Office | 191 | Cook | 41 52 43 N | 087 48 51 W |
| Forest Park South Nature Preserve | Park | | Peoria | 40 45 07 N | 089 34 18 W |
| Forest Park Village Hall | Building | 191 | Cook | 41 52 37 N | 087 48 53 W |
| Forest Plaza Shopping Center | Locale | 265 | Winnebago | 42 15 55 N | 088 59 41 W |
| Forest Preserve Bible Church | Church | 197 | Cook | 41 57 04 N | 087 48 49 W |
| Forest Preserve Park | Park | 204 | Piatt | 40 02 22 N | 088 34 19 W |
| Forest Ridge Church | Church | 126 | Wayne | 38 34 08 N | 088 11 01 W |
| Forest Ridge School | School | 201 | Cook | 41 37 15 N | 087 44 44 W |
| Forest River | Populated Place | 194 | Cook | 42 04 36 N | 087 53 42 W |
| Forest Road Elementary School | School | 190 | Cook | 41 49 53 N | 087 52 03 W |
| Forest School | School | 230 | Lake | 42 23 53 N | 088 10 42 W |
| Forest School (historical) | School | 158 | Clay | 38 39 51 N | 088 40 36 W |
| Forest School (historical) | School | 197 | Edgar | 39 40 21 N | 087 35 54 W |
| Forest School (historical) | School | 131 | Jackson | 37 56 13 N | 089 18 04 W |
| Forest School (historical) | School | 207 | Moultrie | 39 35 11 N | 088 42 30 W |
| Forest Trail Junior High School | School | 216 | Cook | 41 29 10 N | 087 41 47 W |
| Forest Valley School (historical) | School | 185 | Morgan | 39 34 02 N | 089 57 15 W |
| Forest View | Populated Place | 181 | Cook | 41 48 31 N | 087 47 36 W |
| Forest View Elementary School | School | 211 | Cook | 42 03 15 N | 087 58 00 W |
| Forest View High School | School | 212 | Cook | 42 02 47 N | 087 58 23 W |
| Forest View Park | Park | 212 | DuPage | 41 47 22 N | 088 11 08 W |
| Forest View Park | Park | 235 | Lake | 42 25 36 N | 088 01 05 W |
| Forest View School (historical) | School | 232 | Henry | 41 20 17 N | 090 17 57 W |
| Forest View School (historical) | School | 201 | Moultrie | 39 40 40 N | 088 40 32 W |
| Forest View Shopping Center | Locale | 260 | Cook | 42 05 33 N | 088 07 23 W |
| Forest View Village Hall | Building | 181 | Cook | 41 48 32 N | 087 47 51 W |
| Forestview Cemetery | Cemetery | 122 | Pulaski | 37 16 07 N | 089 01 23 W |
| Forestview School (historical) | School | 120 | Pulaski | 37 16 20 N | 089 01 24 W |
| Forestville (subdivision) | Populated Place | 183 | Cook | 41 48 45 N | 087 36 43 W |
| Forestville North School | School | 183 | Cook | 41 48 51 N | 087 36 57 W |
| Fork Creek | Stream | | Madison | 38 40 42 N | 089 48 12 W |
| Fork Prairie School (historical) | School | 173 | Sangamon | 39 47 19 N | 089 30 57 W |
| Forked Creek | Stream | | Will | 41 18 47 N | 088 09 00 W |
| Forked Lake (historical) | Lake | 110 | Jackson | 37 42 55 N | 089 32 19 W |
| Forkosh Hospital | Hospital | 179 | Cook | 41 57 42 N | 087 41 33 W |
| Forman | Populated Place | 107 | Johnson | 37 20 48 N | 088 54 26 W |
| Forman Cemetery | Cemetery | 191 | Pike | 39 36 07 N | 090 44 38 W |
| Forman Creek | Stream | | Knox | 41 05 32 N | 090 07 26 W |
| Forman Memorial Methodist Episcopal Church (historical) | Church | 157 | Washington | 38 20 35 N | 089 22 49 W |
| Forman School (historical) | School | 200 | Kankakee | 41 07 58 N | 087 59 47 W |
| Formosa | Locale | 173 | Madison | 38 43 01 N | 089 54 46 W |
| Formosa Junction | Populated Place | 167 | Madison | 38 42 26 N | 089 55 41 W |
| Forrest | Populated Place | 209 | Livingston | 40 45 07 N | 088 24 40 W |
| Forrest Cemetery | Cemetery | 210 | Livingston | 40 44 20 N | 088 24 30 W |
| Forrest Hill Plaza Shopping Center | Locale | 188 | Peoria | 40 43 29 N | 089 37 29 W |
| Forrest Hill School (historical) | School | 168 | St. Clair | 38 30 21 N | 090 07 09 W |
| Forrest Hill United Methodist Church | Church | 195 | Peoria | 40 43 28 N | 089 35 10 W |
| Forrest School (historical) | School | 158 | Madison | 38 43 17 N | 089 36 38 W |
| Forrest W Wood Access Area | Park | 189 | Moultrie | 39 33 05 N | 088 37 20 W |
| Forrestal Elementary School | School | 211 | Lake | 42 18 07 N | 087 51 59 W |
| Forreston | Populated Place | 286 | Ogle | 42 07 34 N | 089 34 45 W |
| Forreston City Hall | Building | 286 | Ogle | 42 07 36 N | 089 34 44 W |
| Forreston Grade and Junior High School | School | 285 | Ogle | 42 07 26 N | 089 34 42 W |
| Forreston Grove Cemetery | Cemetery | 288 | Ogle | 42 06 59 N | 089 37 42 W |
| Forreston Grove Church | Church | 287 | Ogle | 42 06 59 N | 089 37 40 W |
| Forreston High School | School | 282 | Ogle | 42 07 38 N | 089 34 20 W |
| Forreston Post Office | Post Office | 285 | Ogle | 42 07 36 N | 089 34 41 W |
| Forreston Station | Locale | 269 | Ogle | 42 09 05 N | 089 35 20 W |
| Forrestville Hyde Park Congregation of Jehovah Witnesses | Church | 183 | Cook | 41 48 10 N | 087 37 26 W |
| Forse Cemetery | Cemetery | 194 | Vermilion | 40 03 35 N | 087 34 07 W |
| Forsyth | Populated Place | 207 | Macon | 39 55 57 N | 088 57 04 W |
| Forsyth Baptist Church | Church | 207 | Macon | 39 55 49 N | 088 57 14 W |
| Forsyth Building | Building | 193 | Cook | 41 53 18 N | 087 48 04 W |
| Forsyth Cemetery | Cemetery | 204 | Hancock | 40 12 07 N | 091 07 22 W |
| Forsyth Grade School | School | 205 | Macon | 39 56 03 N | 088 57 10 W |
| Forsyth Post Office | Post Office | 207 | Macon | 39 55 58 N | 088 57 03 W |
| Forsyth Public Library | Building | 207 | Macon | 39 55 59 N | 088 57 03 W |
| Forsyth Recreation Center | Park | 205 | Macon | 39 55 48 N | 088 57 02 W |
| Forsyth United Methodist Church | Church | 207 | Macon | 39 55 58 N | 088 57 07 W |
| Forsyth Village Hall | Building | 204 | Macon | 39 55 55 N | 088 57 21 W |
| Forsythe Cemetery | Cemetery | 190 | Clark | 39 27 51 N | 087 41 08 W |
| Forsythe Woods County Forest Preserve | Park | 166 | Will | 41 18 15 N | 088 07 31 W |
| Fort Cavendish (historical) | Military (Historical) | 121 | Randolph | 38 05 04 N | 090 09 28 W |
| Fort Charters Sportsmans Club Lake | Reservoir | 137 | Randolph | 38 03 30 N | 090 02 30 W |
| Fort Charters Sportsmans Club Lake Dam | Dam | 137 | Randolph | 38 03 30 N | 090 02 30 W |
| Fort Chartres Island | Island | 117 | Randolph | 38 04 51 N | 090 10 17 W |
| Fort Chartres State Park | Park | 121 | Randolph | 38 05 05 N | 090 09 30 W |
| Fort Clark (historical) | Military (Historical) | 138 | Peoria | 40 41 16 N | 089 35 25 W |
| Fort Creve Coeur State Park | Park | 177 | Tazewell | 40 38 57 N | 089 36 22 W |
| Fort Daniel Conservation Area | Park | 200 | Macon | 39 46 40 N | 088 49 32 W |
| Fort Daniel School (historical) | School | 207 | Macon | 39 47 01 N | 088 49 40 W |
| Fort Davenport Historical Monument | Park | 175 | Rock Island | 41 31 01 N | 090 33 54 W |
| Fort Dearborn (historical) | Military (Historical) | 178 | Cook | 41 53 17 N | 087 37 26 W |
| Fort Dearborn Addition (subdivision) | Populated Place | 180 | Cook | 41 53 07 N | 087 37 30 W |
| Fort Dearborn Elementary School | School | 185 | Cook | 41 43 48 N | 087 39 18 W |
| Fort Defiance State Park | Park | 96 | Alexander | 36 59 11 N | 089 08 45 W |
| Fort Dever Cemetery | Cemetery | 204 | Marshall | 40 57 24 N | 089 18 39 W |
| Fort Gage | Populated Place | 116 | Randolph | 37 57 38 N | 089 54 16 W |
| Fort Henry School (historical) | School | 229 | Knox | 40 57 40 N | 090 11 05 W |