22 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 8540 | Princeton | 48,513 |
| 8618 | Trenton | 39,047 |
| 8610 | Trenton | 32,324 |
| 8611 | Trenton | 31,660 |
| 8648 | Lawrence Township | 31,626 |
| 8520 | Hightstown | 29,296 |
| 8638 | Trenton | 23,804 |
| 8619 | Trenton | 23,446 |
| 8550 | Princeton Junction | 20,954 |
| 8690 | Trenton | 19,959 |
| 8691 | Robbinsville | 16,935 |
| 8629 | Trenton | 13,075 |
| 8534 | Pennington | 12,990 |
| 8620 | Trenton | 12,913 |
| 8609 | Trenton | 12,799 |
| 8628 | Trenton | 9,107 |
| 8525 | Hopewell | 4,554 |
| 8544 | Princeton | 4,504 |
| 8560 | Titusville | 3,689 |
| 8542 | Princeton | 2,595 |
| 8608 | Trenton | 786 |
| 8561 | Windsor | 328 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 22 ZCTAs in Mercer County, New Jersey (US Census).