| Name | What | Region | Country | Lat | Long | Elev Ft. | Pop Est |
| Abbot | city | Illinois | United States | 37.55722 | -88.69889 | 498 | 952 |
| Abingdon | city | Illinois | United States | 40.80444 | -90.40167 | 741 | 2101 |
| Adair | city | Illinois | United States | 40.41889 | -90.49667 | 649 | 667 |
| Adams | city | Illinois | United States | 39.86528 | -91.19806 | 754 | 882 |
| Adams Corner | city | Illinois | United States | 38.51306 | -87.74194 | 462 | 1073 |
| Adams historical | city | Illinois | United States | 41.09944 | -88.58472 | 698 | 1408 |
| Addieville | city | Illinois | United States | 38.39139 | -89.49 | 492 | 1074 |
| Addison | city | Illinois | United States | 41.93167 | -87.98889 | 675 | 142253 |
| Adeline | city | Illinois | United States | 42.14333 | -89.49028 | 797 | 1478 |
| Aden | city | Illinois | United States | 38.24167 | -88.45833 | 380 | 731 |
| Adenmoor | city | Illinois | United States | 39.36583 | -87.79667 | 600 | 1293 |
| Adrian | city | Illinois | United States | 40.52083 | -91.16694 | 692 | 1045 |
| Advance | city | Illinois | United States | 39.15667 | -88.02889 | 554 | 784 |
| Afolkey | city | Illinois | United States | 42.4325 | -89.57444 | 908 | 1751 |
| Afton Center | city | Illinois | United States | 41.84917 | -88.77361 | 892 | 5371 |
| Agnew | city | Illinois | United States | 41.78667 | -89.8 | 649 | 2509 |
| Ahern | city | Illinois | United States | 41.15417 | -87.60472 | 626 | 3595 |
| Aiken | city | Illinois | United States | 42.3525 | -90.41528 | 600 | 2167 |
| Akin | city | Illinois | United States | 37.98806 | -88.7475 | 485 | 1027 |
| Akin Junction | city | Illinois | United States | 38.01 | -88.76139 | 452 | 1209 |
| Akron | city | Illinois | United States | 40.90389 | -89.65389 | 711 | 2171 |
| Aladdin | city | Illinois | United States | 39.71639 | -91.32306 | 469 | 7011 |
| Alandale | city | Illinois | United States | 38.93889 | -90.22917 | 597 | 20785 |
| Albany | city | Illinois | United States | 41.78944 | -90.21917 | 649 | 6609 |
| Albany Park subdivision | city | Illinois | United States | 41.96833 | -87.72333 | 593 | 590747 |
| Albers | city | Illinois | United States | 38.54333 | -89.61222 | 426 | 4665 |
| Albion | city | Illinois | United States | 38.3775 | -88.05611 | 492 | 3146 |
| Alda | city | Illinois | United States | 38.46278 | -89.23667 | 452 | 1925 |
| Alden | city | Illinois | United States | 42.45889 | -88.51778 | 1000 | 3579 |
| Aldine Square subdivision | city | Illinois | United States | 41.82611 | -87.6125 | 587 | 387164 |
| Aldridge | city | Illinois | United States | 37.55833 | -89.47 | 347 | 925 |
| Aledo | city | Illinois | United States | 41.19972 | -90.74917 | 711 | 4480 |
| Alexander | city | Illinois | United States | 39.72444 | -90.03806 | 649 | 1162 |
| Alexis | city | Illinois | United States | 41.06333 | -90.55583 | 698 | 907 |
| Alexis Junction | city | Illinois | United States | 41.06722 | -90.63833 | 646 | 948 |
| Algonquin | city | Illinois | United States | 42.16556 | -88.29417 | 757 | 46295 |
| Alhambra | city | Illinois | United States | 38.88833 | -89.73139 | 564 | 1769 |
| Aliceville | city | Illinois | United States | 41.55222 | -89.87944 | 620 | 839 |
| Allen | city | Illinois | United States | 40.305 | -89.64944 | 538 | 1025 |
| Allendale | city | Illinois | United States | 38.52667 | -87.70972 | 462 | 1073 |
| Allens Corners | city | Illinois | United States | 42.09944 | -88.48139 | 990 | 4004 |
| Allens Spring | city | Illinois | United States | 37.36889 | -88.65694 | 400 | 761 |
| Allentown | city | Illinois | United States | 40.55583 | -89.39667 | 666 | 6566 |
| Allenville | city | Illinois | United States | 39.55556 | -88.52972 | 649 | 1374 |
| Allerton | city | Illinois | United States | 39.91167 | -87.93639 | 659 | 882 |
| Allright | city | Illinois | United States | 39.29722 | -87.74889 | 600 | 960 |
| Alma | city | Illinois | United States | 38.72167 | -88.90917 | 633 | 1052 |
| Almora | city | Illinois | United States | 42.06083 | -88.33611 | 816 | 39046 |
| Almora Heights | city | Illinois | United States | 42.04278 | -88.34389 | 836 | 39046 |
| Alonzo | city | Illinois | United States | 40.56667 | -87.73111 | 666 | 821 |
| Alorton | city | Illinois | United States | 38.58972 | -90.12 | 413 | 74662 |
| Alpha | city | Illinois | United States | 41.19167 | -90.38 | 800 | 1011 |
| Alpine | city | Illinois | United States | 41.58639 | -87.88139 | 721 | 42002 |
| Alsey | city | Illinois | United States | 39.56056 | -90.43389 | 600 | 1242 |
| Alsip | city | Illinois | United States | 41.66889 | -87.73861 | 610 | 229138 |
| Alta | city | Illinois | United States | 40.81083 | -89.63417 | 800 | 20939 |
| Altamont | city | Illinois | United States | 38.92306 | -90.20972 | 600 | 20785 |
| Altamont | city | Illinois | United States | 39.06194 | -88.74806 | 613 | 2266 |
| Altgeld Gardens | city | Illinois | United States | 41.65444 | -87.60194 | 587 | 201015 |
| Altmar | city | Illinois | United States | 41.14194 | -88.8925 | 623 | 7563 |
| Alto Pass | city | Illinois | United States | 37.57028 | -89.3175 | 590 | 1114 |
| Alton | city | Illinois | United States | 38.89056 | -90.18417 | 433 | 36560 |
| Altona | city | Illinois | United States | 41.11472 | -90.16444 | 754 | 854 |
| Altorf | city | Illinois | United States | 41.19028 | -87.96222 | 626 | 7584 |
| Alvin | city | Illinois | United States | 40.30833 | -87.60833 | 649 | 1149 |
| Alworth | city | Illinois | United States | 42.24361 | -89.24556 | 898 | 3312 |
| Amboy | city | Illinois | United States | 41.71417 | -89.32861 | 738 | 1806 |
| Amenia | city | Illinois | United States | 40.02194 | -88.66639 | 679 | 2929 |
| Ament Corners | city | Illinois | United States | 41.59722 | -88.43583 | 698 | 4045 |
| America | city | Illinois | United States | 37.13833 | -89.12361 | 360 | 1346 |
| Ames | city | Illinois | United States | 38.14667 | -90.05444 | 498 | 1679 |
| Amity | city | Illinois | United States | 38.77639 | -87.92417 | 472 | 1041 |
| Anchor | city | Illinois | United States | 40.56806 | -88.53556 | 761 | 1132 |
| Ancona | city | Illinois | United States | 41.04056 | -88.8725 | 626 | 1051 |
| Andalusia | city | Illinois | United States | 41.43917 | -90.7175 | 590 | 4503 |
| Anderson | city | Illinois | United States | 39.98222 | -90.15889 | 600 | 1311 |
| Anderson | city | Illinois | United States | 39.34389 | -89.845 | 649 | 1678 |
| Andover | city | Illinois | United States | 41.29389 | -90.29194 | 800 | 2055 |
| Andres | city | Illinois | United States | 41.37167 | -87.8825 | 708 | 3075 |
| Andrew | city | Illinois | United States | 39.89556 | -89.64 | 551 | 7431 |
| Andrews and Hurds Subdivision | city | Illinois | United States | 41.66667 | -87.63194 | 593 | 330162 |
| Anna | city | Illinois | United States | 37.46028 | -89.24694 | 688 | 7044 |
| Annapolis | city | Illinois | United States | 39.14444 | -87.81667 | 557 | 998 |
| Annawan | city | Illinois | United States | 41.39722 | -89.90444 | 626 | 746 |
| Antioch | city | Illinois | United States | 42.47722 | -88.09556 | 770 | 20270 |
| Appalokia historical | city | Illinois | United States | 39.59028 | -89.98778 | 652 | 1257 |
| Apple River | city | Illinois | United States | 42.505 | -90.09861 | 964 | 934 |
| Applegate | city | Illinois | United States | 38.79278 | -87.79667 | 429 | 832 |
| Appleton | city | Illinois | United States | 40.93583 | -90.16083 | 623 | 1083 |
| Aptakisic | city | Illinois | United States | 42.1825 | -87.94722 | 659 | 92659 |
| Arboretum Estates subdivision | city | Illinois | United States | 41.83444 | -88.06611 | 725 | 148881 |
| Arbury Hills | city | Illinois | United States | 41.53556 | -87.8475 | 721 | 37357 |
| Arcade Row subdivision | city | Illinois | United States | 41.69056 | -87.60917 | 587 | 295185 |
| Arcadia | city | Illinois | United States | 39.83917 | -90.24472 | 600 | 1126 |
| Archer | city | Illinois | United States | 39.78139 | -89.73583 | 600 | 36520 |
| Archer Heights subdivision | city | Illinois | United States | 41.81139 | -87.72611 | 603 | 457238 |
| Archer Limits subdivision | city | Illinois | United States | 41.80611 | -87.74944 | 593 | 457238 |
| Archie | city | Illinois | United States | 39.89417 | -87.82833 | 702 | 706 |
| Arcola | city | Illinois | United States | 39.68472 | -88.30639 | 669 | 2309 |
| Arenzville | city | Illinois | United States | 39.87694 | -90.37333 | 488 | 1216 |
| Argenta | city | Illinois | United States | 39.98194 | -88.82278 | 675 | 2528 |
| Argo Fay | city | Illinois | United States | 42.00417 | -90.01722 | 649 | 1042 |
| Argyle | city | Illinois | United States | 42.36 | -88.94 | 898 | 12059 |
| Arlington | city | Illinois | United States | 41.47361 | -89.24917 | 751 | 1223 |
| Arlington Heights | city | Illinois | United States | 39.81972 | -89.60139 | 564 | 70389 |
| Arlington Heights | city | Illinois | United States | 42.08833 | -87.98056 | 698 | 188514 |
| Armington | city | Illinois | United States | 40.33889 | -89.31139 | 603 | 1381 |
| Armour Patch subdivision | city | Illinois | United States | 41.81583 | -87.65861 | 593 | 562172 |
| Armour Square subdivision | city | Illinois | United States | 41.84 | -87.63306 | 593 | 497128 |
| Armsby historical | city | Illinois | United States | 42.47361 | -88.41111 | 898 | 4643 |
| Armstrong | city | Illinois | United States | 40.30639 | -87.87778 | 711 | 971 |
| Arnold | city | Illinois | United States | 42.17 | -90.22639 | 583 | 846 |
| Arnold | city | Illinois | United States | 39.72111 | -90.145 | 633 | 2680 |
| Aroma Park | city | Illinois | United States | 41.07972 | -87.81139 | 603 | 12899 |
| Arpee | city | Illinois | United States | 41.18306 | -90.94694 | 567 | 806 |
| Arrowsmith | city | Illinois | United States | 40.44944 | -88.63167 | 872 | 1022 |
| Arthur | city | Illinois | United States | 39.71472 | -88.47222 | 659 | 1670 |
| Arthur L Johnson Subdivision subdivision | city | Illinois | United States | 42.19278 | -89.07722 | 748 | 34844 |
| Ashburn subdivision | city | Illinois | United States | 41.7475 | -87.71111 | 616 | 311275 |
| Ashdale Junction | city | Illinois | United States | 42.085 | -89.92444 | 807 | 1732 |
| Ashkum | city | Illinois | United States | 40.88028 | -87.955 | 652 | 1133 |
| Ashland | city | Illinois | United States | 39.88778 | -90.00778 | 633 | 995 |
| Ashley | city | Illinois | United States | 38.32944 | -89.19083 | 547 | 912 |
| Ashmore | city | Illinois | United States | 39.53306 | -88.02222 | 672 | 1039 |
| Ashton | city | Illinois | United States | 41.86611 | -89.22111 | 797 | 1066 |
| Askvig Addition | city | Illinois | United States | 41.94389 | -89.07417 | 800 | 6776 |
| Assumption | city | Illinois | United States | 39.52028 | -89.04889 | 636 | 1077 |
| Astoria | city | Illinois | United States | 40.2275 | -90.35944 | 679 | 1009 |
| Athens | city | Illinois | United States | 39.96083 | -89.72389 | 600 | 1691 |
| Athensville | city | Illinois | United States | 39.45556 | -90.18917 | 590 | 809 |
| Atkinson | city | Illinois | United States | 41.42083 | -90.015 | 666 | 710 |
| Atlanta | city | Illinois | United States | 40.25944 | -89.23333 | 698 | 1278 |
| Atlas | city | Illinois | United States | 39.51389 | -90.96944 | 583 | 616 |
| Atterberry | city | Illinois | United States | 40.06083 | -89.92361 | 600 | 925 |
| Attila | city | Illinois | United States | 37.76972 | -88.77111 | 498 | 1763 |
| Atwater | city | Illinois | United States | 39.33278 | -89.725 | 636 | 865 |
| Atwood | city | Illinois | United States | 39.79944 | -88.46222 | 669 | 1690 |
| Atwood Estates subdivision | city | Illinois | United States | 42.19417 | -89.05167 | 826 | 34844 |
| Atwood Park Estates subdivision | city | Illinois | United States | 42.19111 | -89.05139 | 826 | 34844 |
| Auburn | city | Illinois | United States | 39.59167 | -89.74639 | 626 | 5796 |
| Auburn Park subdivision | city | Illinois | United States | 41.75417 | -87.63667 | 590 | 561977 |
| Augerville | city | Illinois | United States | 40.13972 | -88.17167 | 708 | 40976 |
| Augsburg | city | Illinois | United States | 38.86667 | -89.01333 | 554 | 761 |
| Augusta | city | Illinois | United States | 40.23 | -90.95 | 652 | 729 |
| Aurora | city | Illinois | United States | 41.76056 | -88.32 | 646 | 124397 |
| Austin | city | Illinois | United States | 41.8875 | -87.76472 | 616 | 607131 |
| Aux Sable | city | Illinois | United States | 41.39472 | -88.32861 | 488 | 5496 |
| Ava | city | Illinois | United States | 37.88833 | -89.49472 | 600 | 1079 |
| Avalon Highlands subdivision | city | Illinois | United States | 41.74861 | -87.60194 | 587 | 439529 |
| Avalon Park subdivision | city | Illinois | United States | 41.745 | -87.58861 | 587 | 439529 |
| Avena | city | Illinois | United States | 39.0075 | -88.92778 | 590 | 1218 |
| Avery Hill | city | Illinois | United States | 38.55306 | -90.02694 | 534 | 68616 |
| Averyville | city | Illinois | United States | 40.71667 | -89.56222 | 439 | 74835 |
| Aviston | city | Illinois | United States | 38.60667 | -89.6075 | 446 | 5013 |
| Avoca historical | city | Illinois | United States | 40.80611 | -88.51806 | 649 | 1238 |
| Avon | city | Illinois | United States | 40.66417 | -90.43472 | 603 | 1355 |
| Avondale subdivision | city | Illinois | United States | 41.93889 | -87.71111 | 600 | 722202 |
| Ayers | city | Illinois | United States | 42.05389 | -90.11556 | 600 | 3234 |
| Ayers | city | Illinois | United States | 38.96361 | -89.45194 | 577 | 1517 |