Douwemastins is een straat te Leeuwarden in de gemeente Leeuwarden en is gelegen in de Nederlandse provincie Friesland.
| Postcode | Huisnummers |
|---|---|
| 8925 EB | 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 4, 2, 34; |
| 8925 EA | 43, 41, 39, 37, 35, 33, 31, 29, 27, 25, 23, 21, 19, 17, 15, 13, 11, 9, 7, 5, 3, 1; |