20 ZIP Codes
| Zip Code | City | Population ↓ |
|---|---|---|
| 21014 | Bel Air | 38,707 |
| 21009 | Abingdon | 33,679 |
| 21015 | Bel Air | 30,013 |
| 21001 | Aberdeen | 27,168 |
| 21040 | Edgewood | 24,960 |
| 21078 | Havre De Grace | 20,030 |
| 21050 | Forest Hill | 17,466 |
| 21085 | Joppa | 17,307 |
| 21047 | Fallston | 13,852 |
| 21084 | Jarrettsville | 7,070 |
| 21017 | Belcamp | 6,648 |
| 21154 | Street | 6,544 |
| 21161 | White Hall | 5,221 |
| 21132 | Pylesville | 3,160 |
| 21028 | Churchville | 3,103 |
| 21034 | Darlington | 2,846 |
| 21160 | Whiteford | 2,441 |
| 21005 | Aberdeen Proving Ground | 2,202 |
| 21010 | Gunpowder | 239 |
| 21130 | Perryman | 112 |
The data shown reflect ZCTAs from the US Census. As of 2025, there are 20 ZCTAs in Harford County, Maryland (US Census).