Area Code 779
Area code 779 is in Illinois, USA , spanning 24 counties and serving 248 cities, including Joliet, Dekalb or Crystal Lake; it currently uses 309 prefixes, assigned from 779-200-XXXX through 779-999-XXXX.
In service since March 17, 2007, area code 779 is an overlay Numbering Plan Area, part of overlay complex 815/779.
The current local time is .
For exact NPA boundaries see official 779 area code map
More Illinois area codes:
Reverse phone lookup
Locate any 779-NXX prefix:
| NPANXX | Area served1 | Date2 |
|---|---|---|
| 779-200 | Rockford | 1/18/2011 |
| 779-201 | La Salle | 3/15/2012 |
| 779-202 | Galena | 3/6/2012 |
| 779-203 | Rockford | 10/13/2011 |
| 779-204 | Verona | 3/19/2014 |
| 779-205 | Joliet | 5/30/2012 |
| 779-206 | Joliet | 6/20/2012 |
| 779-207 | Rockford | N/A |
| 779-208 | Rockford | 11/16/2012 |
| 779-209 | Sandwich | 8/31/2012 |
| 779-210 | Rockford | 9/16/2011 |
| 779-212 | De Kalb | 3/13/2013 |
| 779-213 | Oglesby | 4/9/2013 |
| 779-214 | Galena | 12/17/2009 |
| 779-215 | Tonica | 4/9/2013 |
| 779-216 | Frankfort | 4/9/2013 |
| 779-217 | De Kalb | 05/19/2023 |
| 779-218 | Watseka | 4/9/2013 |
| 779-219 | Braidwood | 08/11/2023 |
| 779-220 | Crystal Lake | 5/25/2011 |
| 779-221 | Rockford | 4/2/2010 |
| 779-222 | Sycamore | 8/5/2010 |
| 779-223 | Onarga | 3/23/2016 |
| 779-224 | Momence | 06/08/2023 |
| 779-225 | Joliet | 9/21/2011 |
| 779-226 | Polo | 4/24/2013 |
| 779-227 | Joliet | 7/1/2014 |
| 779-228 | Mazon | 4/10/2013 |
| 779-229 | Depue | 5/7/2013 |
| 779-230 | Joliet | 9/28/2016 |
| 779-231 | Joliet | 12/21/2015 |
| 779-232 | Wilmington | 6/7/2007 |
| 779-233 | Joliet | 7/21/2011 |
| 779-234 | Plainfield | 8/1/2013 |
| 779-235 | Crescent City | 2/4/2011 |
| 779-236 | Kankakee | 7/27/2011 |
| 779-237 | Streator | 1/8/2018 |
| 779-238 | Rockford | 4/4/2017 |
| 779-239 | Princeton | 1/14/2016 |
| 779-240 | Kankakee | 6/11/2014 |
| 779-241 | Morris | 6/1/2017 |
| 779-242 | Joliet | 10/5/2017 |
| 779-243 | Frankfort | 10/5/2017 |
| 779-244 | Mchenry | 10/5/2017 |
| 779-245 | Sterling | 7/14/2008 |
| 779-246 | Rochelle | 10/23/2017 |
| 779-247 | Woodstock | 12/1/2017 |
| 779-248 | Galena | 6/3/2016 |
| 779-249 | Dwight | 2/22/2018 |
| 779-250 | Sterling | 2/27/2018 |
| 779-251 | Dixon | 4/1/2014 |
| 779-252 | Plainfield | 1/6/2016 |
| 779-253 | South Beloit | 10/7/2014 |
| 779-254 | Frankfort | 9/1/2015 |
| 779-255 | De Kalb | 5/16/2018 |
| 779-256 | Rockford | 6/5/2018 |
| 779-257 | Wilmington | 7/11/2018 |
| 779-258 | Herscher | 8/27/2018 |
| 779-259 | Manteno | 8/27/2018 |
| 779-260 | Joliet | 10/8/2018 |
| 779-261 | Fairbury | 11/30/2018 |
| 779-262 | Oglesby | 12/5/2018 |
| 779-263 | Plainfield | 1/2/2018 |
| 779-264 | Kankakee | 10/7/2019 |
| 779-265 | Mchenry | 10/8/2019 |
| 779-266 | Lanark | 12/9/2019 |
| 779-267 | Joliet | 1/17/2020 |
| 779-268 | St Anne | 2/6/2020 |
| 779-269 | Rockford | 2/10/2020 |
| 779-270 | De Kalb | 2/19/2020 |
| 779-271 | Lanark | 4/29/2020 |
| 779-272 | Rockford | 5/1/2020 |
| 779-273 | Danforth | 5/28/2020 |
| 779-274 | Rockford | 6/26/2020 |
| 779-275 | Rockford | 7/28/2020 |
| 779-276 | De Kalb | 7/28/2020 |
| 779-277 | Flanagan | 8/12/2020 |
| 779-278 | Grand Ridge | 3/18/2021 |
| 779-279 | Joliet | 10/29/2008 |
| 779-280 | Donovan | 8/25/2020 |
| 779-281 | Toluca | 8/12/2020 |
| 779-282 | Martinton | 8/25/2020 |
| 779-283 | Richmond | 8/25/2020 |
| 779-284 | Sheldon | 8/25/2020 |
| 779-285 | Sheridan | 8/25/2020 |
| 779-286 | Spring Grove | 8/25/2020 |
| 779-287 | Union | 3/24/2016 |
| 779-288 | Beaverville | 6/2/2021 |
| 779-289 | South Beloit | 9/1/2020 |
| 779-290 | Milford | 9/2/2020 |
| 779-291 | Wonder Lake | 9/4/2020 |
| 779-292 | Onarga | 9/4/2020 |
| 779-293 | New Lenox | 9/4/2020 |
| 779-294 | Harding | 9/4/2020 |
| 779-295 | Mazon | 9/4/2020 |
| 779-296 | Long Point | 9/8/2020 |
| 779-297 | Sterling | 9/15/2020 |
| 779-298 | Forrest | 9/15/2020 |
| 779-299 | Wenona | 9/17/2020 |
| NPANXX | Area served1 | Date2 |
|---|---|---|
| 779-300 | Rockford | 2/17/2011 |
| 779-301 | Kankakee | 6/11/2014 |
| 779-302 | Woodstock | 2/27/2015 |
| 779-303 | Plainfield | N/A |
| 779-304 | Rutland | 9/17/2020 |
| 779-305 | Reddick | 9/17/2020 |
| 779-306 | Pontiac | 9/17/2020 |
| 779-307 | Lostant | 9/17/2020 |
| 779-308 | Chatsworth | 9/17/2020 |
| 779-309 | South Sharon | 06/13/2023 |
| 779-310 | New Milford | 9/17/2020 |
| 779-312 | Woodstock | 06/21/2023 |
| 779-313 | Cherry Valley | 9/17/2020 |
| 779-314 | Rock Cut | 9/17/2020 |
| 779-315 | Roscoe | 9/17/2020 |
| 779-316 | Creston | 9/17/2020 |
| 779-317 | Kirkland | 9/17/2020 |
| 779-318 | Malta | 9/17/2020 |
| 779-319 | Maple Park | 9/17/2020 |
| 779-320 | Monroe Center | 9/17/2020 |
| 779-321 | Shabbona | 9/17/2020 |
| 779-322 | Thomas | 9/17/2020 |
| 779-323 | Rockford | 9/30/2020 |
| 779-324 | Frankfort | 8/17/2010 |
| 779-325 | Franklin Grove | 11/25/2020 |
| 779-326 | Dwight | 12/10/2020 |
| 779-327 | Warren | 6/10/2021 |
| 779-328 | Hanover | 6/10/2021 |
| 779-329 | Mendota | 6/10/2021 |
| 779-330 | Belvidere | 6/22/2021 |
| 779-331 | Kankakee | 07/18/2023 |
| 779-332 | Durand | 6/10/2021 |
| 779-333 | Frankfort | 4/11/2013 |
| 779-334 | De Kalb | 11/4/2020 |
| 779-335 | Rockford | 6/23/2021 |
| 779-336 | Woodstock | 2/10/2021 |
| 779-337 | Woodland | 6/24/2021 |
| 779-338 | Crescent City | 6/24/2021 |
| 779-339 | Frankfort | 10/19/2021 |
| 779-340 | Coal City | 11/22/2021 |
| 779-341 | Joliet | 12/29/2021 |
| 779-342 | Dwight | 7/14/2021 |
| 779-343 | German Valley | 11/4/2021 |
| 779-344 | Seward | 11/4/2021 |
| 779-345 | Byron | 7/27/2020 |
| 779-346 | Capron | 9/18/2020 |
| 779-347 | Winslow | 11/4/2021 |
| 779-348 | Rockford | 6/13/2007 |
| 779-349 | Spring Valley | 1/11/2022 |
| 779-350 | Momence | 10/3/2022 |
| 779-351 | Rockford | 2/25/2022 |
| 779-352 | Waterman | 1/28/2022 |
| 779-353 | Forreston | 3/31/2022 |
| 779-354 | Davis | 3/31/2022 |
| 779-355 | Harmon | 3/31/2022 |
| 779-356 | Crystal Lake | 7/14/2020 |
| 779-357 | Leaf River | 4/12/2022 |
| 779-358 | Plainfield | 10/18/2022 |
| 779-359 | Belvidere | 11/15/2022 |
| 779-360 | Momence | 12/29/2022 |
| 779-361 | Kankakee | 01/03/2023 |
| 779-362 | Fairbury | 01/19/2023 |
| 779-363 | Rockford | 02/08/2023 |
| 779-364 | Streator | 02/08/2023 |
| 779-365 | De Kalb | 02/15/2023 |
| 779-366 | Rockford | 03/08/2023 |
| 779-367 | Sycamore | 03/10/2023 |
| 779-368 | New Milford | 8/21/2007 |
| 779-369 | Momence | 03/16/2023 |
| 779-370 | Rockford | 04/18/2023 |
| 779-371 | Momence | 07/18/2023 |
| 779-372 | Dixon | 07/20/2023 |
| 779-373 | Rockford | 07/20/2023 |
| 779-374 | Joliet | 07/26/2023 |
| 779-375 | Joliet | 07/26/2023 |
| 779-376 | Grant Park | 08/11/2023 |
| 779-377 | South Beloit | 9/13/2021 |
| 779-378 | Mchenry | 08/18/2023 |
| 779-379 | Joliet | 10/29/2008 |
| 779-380 | Momence | 09/06/2023 |
| 779-381 | La Salle | 10/19/2023 |
| 779-382 | Genoa | 5/7/2007 |
| 779-383 | Momence | 10/30/2023 |
| 779-384 | Harvard | 01/09/2024 |
| 779-385 | Momence | 02/06/2024 |
| 779-386 | Princeton | 02/08/2024 |
| 779-387 | Poplar Grove | 03/21/2024 |
| 779-388 | Crystal Lake | 03/22/2024 |
| 779-389 | Garden Prairie | 4/19/2021 |
| 779-390 | Lockport | 03/27/2024 |
| 779-391 | New Lenox | 03/29/2024 |
| 779-392 | Oglesby | 03/29/2024 |
| 779-393 | Watseka | 03/29/2024 |
| 779-394 | Wellington | 03/29/2024 |
| 779-395 | Minooka | 04/02/2024 |
| 779-396 | Woodstock | 04/05/2024 |
| 779-397 | Cabery | 05/03/2023 |
| 779-398 | Pontiac | 05/14/2024 |
| 779-399 | Kinsman | 1/8/2021 |
| NPANXX | Area served1 | Date2 |
|---|---|---|
| 779-400 | De Kalb | 2/17/2011 |
| 779-401 | Kankakee | 04/11/2024 |
| 779-402 | Momence | 04/30/2024 |
| 779-403 | Mchenry | 06/25/2024 |
| 779-404 | Rochelle | 07/08/2024 |
| 779-410 | Stockton | 3/30/2021 |
| 779-423 | Rockford | 8/8/2007 |
| 779-426 | Manhattan | 1/13/2022 |
| 779-429 | Wilmington | 11/13/2008 |
| 779-432 | Sheffield | 3/27/2007 |
| 779-435 | Joliet | 11/13/2006 |
| 779-444 | Wonder Lake | 8/17/2010 |
| 779-445 | Lockport | 11/8/2022 |
| 779-456 | Joliet | 1/9/2008 |
| 779-463 | Morris | 3/23/2022 |
| 779-465 | Braidwood | 10/10/2019 |
| 779-466 | Emington | 1/26/2022 |
| 779-475 | South Beloit | 3/27/2007 |
| 779-479 | Graymont | 4/18/2021 |
| 779-499 | Freeport | 9/13/2021 |
| NPANXX | Area served1 | Date2 |
|---|---|---|
| 779-600 | Cissna Park | 8/8/2019 |
| 779-601 | La Salle | 9/10/2014 |
| 779-624 | Momence | 1/13/2022 |
| 779-625 | Woodstock | 2/23/2022 |
| 779-639 | Mchenry | 1/13/2022 |
| 779-666 | Rockford | 10/3/2017 |
| 779-675 | Ohio | 1/13/2022 |
| 779-677 | Freeport | 7/27/2020 |
| 779-678 | Rockford | 1/12/2021 |
| 779-679 | Magnolia | 4/18/2021 |
| 779-696 | Rockford | 8/18/2010 |
| 779-699 | South Beloit | 7/17/2020 |
| NPANXX | Area served1 | Date2 |
|---|---|---|
| 779-701 | Kankakee | 1/28/2015 |
| 779-702 | Joliet | 6/11/2014 |
| 779-703 | Joliet | 10/7/2013 |
| 779-704 | Mchenry | 10/31/2013 |
| 779-706 | Sandwich | 2/24/2015 |
| 779-707 | Joliet | 4/21/2015 |
| 779-710 | Rockford | 3/18/2021 |
| 779-713 | Woodstock | 5/22/2015 |
| 779-717 | Spring Valley | 10/15/2015 |
| 779-722 | Ashton | 9/18/2020 |
| 779-729 | Lena | 4/13/2021 |
| 779-732 | La Salle | 2/10/2021 |
| 779-739 | Forrest | 2/14/2022 |
| 779-746 | Cissna Park | 1/13/2022 |
| 779-749 | Steward | 4/13/2021 |
| 779-758 | Joliet | 10/11/2019 |
| 779-759 | Sycamore | 4/13/2021 |
| 779-766 | Depue | 7/14/2020 |
| 779-770 | Rockford | 11/18/2008 |
| 779-771 | Rockford | 11/18/2008 |
| 779-772 | Rockford | 11/18/2008 |
| 779-774 | Rockford | 2/1/2012 |
| 779-775 | De Kalb | 9/13/2021 |
| 779-777 | De Kalb | 10/22/2008 |
| 779-778 | Winnebago | 5/28/2020 |
| 779-783 | Stockland | 1/13/2022 |
| 779-788 | Pecatonica | 1/28/2021 |
| 779-789 | Rockton | 4/19/2021 |
| 779-790 | Sterling | 04/12/2023 |
| 779-797 | Rockford | 9/23/2021 |
| 779-799 | Coleta | 7/27/2020 |
| NPANXX | Area served1 | Date2 |
|---|---|---|
| 779-800 | Crystal Lake | 4/11/2013 |
| 779-801 | Kankakee | 9/7/2016 |
| 779-803 | New Lenox | 8/16/2013 |
| 779-804 | Pontiac | 2/24/2015 |
| 779-809 | Fulton | 3/28/2022 |
| 779-832 | Cedar Point | 1/13/2022 |
| 779-837 | Elwood | 1/7/2022 |
| 779-855 | Forrest | 3/31/2021 |
| 779-861 | Dixon | 5/26/2010 |
| 779-867 | Rockford | 4/12/2021 |
| 779-875 | Joliet | 7/12/2007 |
| 779-877 | Verona | 7/14/2020 |
| 779-879 | Streator | 4/18/2021 |
| 779-888 | Rockford | 1/28/2015 |
| 779-895 | Rockford | 2/1/2022 |
| 779-899 | Lisbon | 7/14/2020 |
| NPANXX | Area served1 | Date2 |
|---|---|---|
| 779-900 | Frankfort | 9/17/2019 |
| 779-901 | Marengo | 4/30/2015 |
| 779-902 | De Kalb | 3/19/2021 |
| 779-903 | Braidwood | 7/29/2013 |
| 779-904 | Freeport | 3/24/2021 |
| 779-910 | De Kalb | 3/18/2021 |
| 779-915 | Woodstock | 11/16/2016 |
| 779-922 | Hooppole | 7/27/2020 |
| 779-927 | Marengo | 1/13/2022 |
| 779-931 | Sandwich | 10/27/2016 |
| 779-933 | Hinckley | 7/27/2020 |
| 779-939 | Joliet | 2/3/2016 |
| 779-946 | Granville | 7/14/2020 |
| 779-970 | Rockford | 9/14/2015 |
| 779-977 | Harvard | 7/14/2020 |
| 779-978 | Sandwich | 6/4/2015 |
| 779-979 | Piper City | 4/19/2021 |
| 779-990 | Forrest | 4/12/2021 |
| 779-991 | Leland | 8/12/2020 |
| 779-994 | Crystal Lake | 4/10/2013 |
| 779-997 | Plattville | 1/13/2022 |
| 779-999 | Newark | 9/24/2010 |
- For 'Area served' we list the rate center. In the North American Numbering Plan a rate center is a geographic area used to determine local calling boundaries for billing purposes. Its name is generally a locality, often not the only one served by an NPA-NXX combination.
- Assignment date. N/A - mostly central office codes assigned before 2001.
- NXX prefixes last updated: August 27, 2024
Cities in area code 779
| City1 | County | Time2 |
|---|---|---|
| Alden | McHenry | C |
| Amboy | Lee | C |
| Ancona | Livingston | C |
| Apple River | Jo Daviess | C |
| Arlington | Bureau | C |
| Aroma Park | Kankakee | C |
| Ashkum | Iroquois | C |
| Ashton | Lee | C |
| Baileyville | Ogle | C |
| Beaverville | Iroquois | C |
| Belvidere | Boone | C |
| Blackstone | Livingston | C |
| Bonfield | Kankakee | C |
| Bourbonnais | Kankakee | C |
| Braceville | Grundy | C |
| Bradley | Kankakee | C |
| Braidwood | Will | C |
| Buckingham | Kankakee | C |
| Bureau | Bureau | C |
| Byron | Ogle | C |
| Cabery | Ford | C |
| Caledonia | Boone | C |
| Campus | Livingston | C |
| Capron | Boone | C |
| Cedar Point | La Salle | C |
| Cedarville | Stephenson | C |
| Chadwick | Carroll | C |
| Chana | Ogle | C |
| Channahon | Will | C |
| Chatsworth | Livingston | C |
| Chebanse | Iroquois | C |
| Chenoa | McLean | C |
| Cherry | Bureau | C |
| Cherry Valley | Winnebago | C |
| Cissna Park | Iroquois | C |
| Clare | Dekalb | C |
| Claytonville | Iroquois | C |
| Clifton | Iroquois | C |
| Coal City | Grundy | C |
| Compton | Lee | C |
| Cornell | Livingston | C |
| Cortland | Dekalb | C |
| Crescent City | Iroquois | C |
| Creston | Ogle | C |
| Crystal Lake | McHenry | C |
| Cullom | Livingston | C |
| Dakota | Stephenson | C |
| Dalzell | Bureau | C |
| Dana | La Salle | C |
| Danforth | Iroquois | C |
| Davis | Stephenson | C |
| Davis Junction | Ogle | C |
| Deer Grove | Whiteside | C |
| Dekalb | Dekalb | C |
| Depue | Bureau | C |
| Dixon | Lee | C |
| Donovan | Iroquois | C |
| Dover | Bureau | C |
| Durand | Winnebago | C |
| Dwight | Livingston | C |
| Earlville | La Salle | C |
| East Dubuque | Jo Daviess | C |
| Eldena | Lee | C |
| Eleroy | Stephenson | C |
| Elizabeth | Jo Daviess | C |
| Elwood | Will | C |
| Emington | Livingston | C |
| Esmond | Dekalb | C |
| Essex | Kankakee | C |
| Fairbury | Livingston | C |
| Flanagan | Livingston | C |
| Forrest | Livingston | C |
| Forreston | Ogle | C |
| Frankfort | Will | C |
| Franklin Grove | Lee | C |
| Freeport | Stephenson | C |
| Fulton | Whiteside | C |
| Galena | Jo Daviess | C |
| Galt | Whiteside | C |
| Garden Prairie | Boone | C |
| Gardner | Grundy | C |
| Genoa | Dekalb | C |
| German Valley | Stephenson | C |
| Gilman | Iroquois | C |
| Goodwine | Iroquois | C |
| Grand Ridge | La Salle | C |
| Grant Park | Kankakee | C |
| Granville | Putnam | C |
| Graymont | Livingston | C |
| Hanover | Jo Daviess | C |
| Harmon | Lee | C |
| Harvard | McHenry | C |
| Hebron | McHenry | C |
| Hennepin | Putnam | C |
| Herscher | Kankakee | C |
| Hinckley | Dekalb | C |
| Holcomb | Ogle | C |
| Homer Glen | Will | C |
| Hooppole | Henry | C |
| Hopkins Park | Kankakee | C |
| Iroquois | Iroquois | C |
| Joliet | Will | C |
| Kankakee | Kankakee | C |
| Kasbeer | Bureau | C |
| Kempton | Ford | C |
| Kent | Stephenson | C |
| Kingston | Dekalb | C |
| Kinsman | Grundy | C |
| Kirkland | Dekalb | C |
| La Moille | Bureau | C |
| La Salle | La Salle | C |
| Ladd | Bureau | C |
| Lanark | Carroll | C |
| Leaf River | Ogle | C |
| Lee | Lee | C |
| Lee Center | Lee | C |
| Leland | La Salle | C |
| Lena | Stephenson | C |
| Leonore | La Salle | C |
| Lindenwood | Ogle | C |
| Lockport | Will | C |
| Long Point | Livingston | C |
| Lostant | La Salle | C |
| Loves Park | Winnebago | C |
| Lyndon | Whiteside | C |
| Machesney Park | Winnebago | C |
| Magnolia | Putnam | C |
| Malden | Bureau | C |
| Malta | Dekalb | C |
| Manhattan | Will | C |
| Manlius | Bureau | C |
| Manteno | Kankakee | C |
| Maple Park | Kane | C |
| Marengo | McHenry | C |
| Mark | Putnam | C |
| Marseilles | La Salle | C |
| Martinton | Iroquois | C |
| Mazon | Grundy | C |
| Mc Connell | Stephenson | C |
| Mc Nabb | Putnam | C |
| McHenry | McHenry | C |
| Mendota | La Salle | C |
| Milford | Iroquois | C |
| Milledgeville | Carroll | C |
| Millington | Kendall | C |
| Minooka | Grundy | C |
| Momence | Kankakee | C |
| Monroe Center | Ogle | C |
| Morris | Grundy | C |
| Morrison | Whiteside | C |
| Mount Carroll | Carroll | C |
| Mount Morris | Ogle | C |
| Nachusa | Lee | C |
| New Bedford | Bureau | C |
| New Lenox | Will | C |
| Newark | Kendall | C |
| Nora | Jo Daviess | C |
| Odell | Livingston | C |
| Oglesby | La Salle | C |
| Ohio | Bureau | C |
| Onarga | Iroquois | C |
| Orangeville | Stephenson | C |
| Oregon | Ogle | C |
| Ottawa | La Salle | C |
| Papineau | Iroquois | C |
| Paw Paw | Lee | C |
| Pearl City | Stephenson | C |
| Pecatonica | Winnebago | C |
| Peru | La Salle | C |
| Piper City | Ford | C |
| Plainfield | Will | C |
| Polo | Ogle | C |
| Pontiac | Livingston | C |
| Poplar Grove | Boone | C |
| Princeton | Bureau | C |
| Prophetstown | Whiteside | C |
| Putnam | Putnam | C |
| Ransom | La Salle | C |
| Reddick | Kankakee | C |
| Richmond | McHenry | C |
| Ridott | Stephenson | C |
| Ringwood | McHenry | C |
| Rochelle | Ogle | C |
| Rock City | Stephenson | C |
| Rock Falls | Whiteside | C |
| Rockford | Winnebago | C |
| Rockton | Winnebago | C |
| Romeoville | Will | C |
| Roscoe | Winnebago | C |
| Rutland | La Salle | C |
| Sandwich | Dekalb | C |
| Saunemin | Livingston | C |
| Savanna | Carroll | C |
| Scales Mound | Jo Daviess | C |
| Seatonville | Bureau | C |
| Seneca | La Salle | C |
| Serena | La Salle | C |
| Seward | Winnebago | C |
| Shabbona | Dekalb | C |
| Shannon | Carroll | C |
| Sheffield | Bureau | C |
| Sheldon | Iroquois | C |
| Sheridan | La Salle | C |
| Shirland | Winnebago | C |
| Somonauk | Dekalb | C |
| South Beloit | Winnebago | C |
| South Wilmington | Grundy | C |
| Spring Grove | McHenry | C |
| Spring Valley | Bureau | C |
| St Anne | Kankakee | C |
| Standard | Putnam | C |
| Sterling | Whiteside | C |
| Steward | Lee | C |
| Stillman Valley | Ogle | C |
| Stockland | Iroquois | C |
| Stockton | Jo Daviess | C |
| Strawn | Livingston | C |
| Streator | La Salle | C |
| Sublette | Lee | C |
| Sycamore | Dekalb | C |
| Tampico | Whiteside | C |
| Thomson | Carroll | C |
| Tiskilwa | Bureau | C |
| Toluca | Marshall | C |
| Tonica | La Salle | C |
| Triumph | La Salle | C |
| Troy Grove | La Salle | C |
| Union | McHenry | C |
| Union Hill | Kankakee | C |
| Utica | La Salle | C |
| Van Orin | Bureau | C |
| Verona | Grundy | C |
| Walnut | Bureau | C |
| Warren | Jo Daviess | C |
| Waterman | Dekalb | C |
| Watseka | Iroquois | C |
| Wedron | La Salle | C |
| Wellington | Iroquois | C |
| Wenona | Marshall | C |
| West Brooklyn | Lee | C |
| Wilmington | Will | C |
| Winnebago | Winnebago | C |
| Winslow | Stephenson | C |
| Wonder Lake | McHenry | C |
| Woodland | Iroquois | C |
| Woodstock | McHenry | C |
| Woosung | Ogle | C |
| Wyanet | Bureau | C |
- Listed above are most places served by USA area code 779. When multiple places in a US state share the same name we list the largest one only. Cities with population over 50,000 are displayed in bold text.
- C stands for Central Time (currently ).