Identifiers: city · town · CDP
| Rank | Community | Population |
|---|---|---|
| 1 | Gary (city), IN | 69,093 |
| 2 | Portage (city), IN | 37,926 |
| 3 | Merrillville (town), IN | 36,444 |
| 4 | Valparaiso (city), IN | 34,151 |
| 5 | Crown Point (city), IN | 33,899 |
| 6 | Hobart (city), IN | 29,752 |
| 7 | Schererville (town), IN | 29,646 |
| 8 | East Chicago (city), IN | 26,370 |
| 9 | Highland (town), IN | 23,984 |
| 10 | Munster (town), IN | 23,894 |
| 11 | St. John (town), IN | 20,303 |
| 12 | Griffith (town), IN | 16,528 |
| 13 | Dyer (town), IN | 16,517 |
| 14 | Cedar Lake (town), IN | 14,106 |
| 15 | Lake Station (city), IN | 13,235 |
| 16 | Lowell (town), IN | 10,680 |
| 17 | Winfield (town), IN | 7,181 |
| 18 | Lakes of the Four Seasons (CDP), IN | 7,091 |
| 19 | Porter (town), IN | 5,210 |
| 20 | South Haven (CDP), IN | 5,084 |