Westerstraat is een straat te Harlingen in de gemeente Harlingen en is gelegen in de Nederlandse provincie Friesland.
| Postcode | Huisnummers |
|---|---|
| 8861 XK | 4A, 4, 6A, 6, 8, 10, 12, 14, 16, 18, 20, 22, 26, 28; |
| 8861 XJ | 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 47; |