22 ZIP Codes
| Zip Code | City | Population ↓ |
|---|---|---|
| 08540 | Princeton | 50,388 |
| 08618 | Trenton | 35,634 |
| 08610 | Trenton | 33,465 |
| 08611 | Trenton | 31,995 |
| 08648 | Lawrence Township | 31,323 |
| 08520 | Hightstown | 29,504 |
| 08619 | Trenton | 24,089 |
| 08638 | Trenton | 22,816 |
| 08550 | Princeton Junction | 21,067 |
| 08690 | Trenton | 18,841 |
| 08691 | Robbinsville | 16,607 |
| 08609 | Trenton | 15,938 |
| 08534 | Pennington | 13,272 |
| 08629 | Trenton | 13,013 |
| 08620 | Trenton | 11,621 |
| 08628 | Trenton | 9,831 |
| 08525 | Hopewell | 4,522 |
| 08544 | Princeton | 4,392 |
| 08560 | Titusville | 3,245 |
| 08542 | Princeton | 2,533 |
| 08608 | Trenton | 1,250 |
| 08561 | Windsor | 325 |
The data shown reflect ZCTAs from the US Census. As of 2025, there are 22 ZCTAs in Mercer County, New Jersey (US Census).