44 ZIP Codes
| Zip Code | City | Population ↓ |
|---|---|---|
| 21234 | Parkville | 66,334 |
| 21117 | Owings Mills | 62,816 |
| 21222 | Dundalk | 59,407 |
| 21228 | Catonsville | 50,492 |
| 21207 | Gwynn Oak | 47,099 |
| 21221 | Essex | 43,487 |
| 21220 | Middle River | 42,824 |
| 21236 | Nottingham | 39,514 |
| 21093 | Lutherville Timonium | 39,100 |
| 21244 | Windsor Mill | 38,208 |
| 21208 | Pikesville | 37,276 |
| 21227 | Halethorpe | 34,907 |
| 21136 | Reisterstown | 32,088 |
| 21237 | Rosedale | 31,425 |
| 21133 | Randallstown | 31,398 |
| 21209 | Baltimore | 30,126 |
| 21030 | Cockeysville | 25,827 |
| 21286 | Towson | 21,853 |
| 21204 | Towson | 19,845 |
| 21128 | Perry Hall | 15,501 |
| 21219 | Sparrows Point | 9,565 |
| 21163 | Woodstock | 7,539 |
| 21120 | Parkton | 7,440 |
| 21131 | Phoenix | 7,141 |
| 21152 | Sparks Glencoe | 6,459 |
| 21013 | Baldwin | 5,610 |
| 21087 | Kingsville | 5,537 |
| 21252 | Towson | 4,865 |
| 21111 | Monkton | 4,714 |
| 21162 | White Marsh | 4,639 |
| 21057 | Glen Arm | 4,386 |
| 21155 | Upperco | 3,313 |
| 21053 | Freeland | 2,929 |
| 21250 | Baltimore | 2,834 |
| 21082 | Hydes | 626 |
| 21153 | Stevenson | 456 |
| 21052 | Fort Howard | 409 |
| 21071 | Glyndon | 404 |
| 21156 | Upper Falls | 204 |
| 21051 | Fork | 172 |
| 21023 | Butler | 66 |
| 21105 | Maryland Line | 36 |
| 21031 | Hunt Valley | 26 |
| 21285 | Towson | 3 |
The data shown reflect ZCTAs from the US Census. As of 2025, there are 44 ZCTAs in Baltimore County, Maryland (US Census).