| Official Name: | Bou Ismaïl |
| Native Name: | بواسماعيل |
| Settlement Type: | Commune and town |
| Pushpin Label Position: | bottom |
| Subdivision Type: | Country |
| Subdivision Name: |  Algeria |
| Subdivision Type1: | Province |
| Subdivision Name1: | Tipaza Province |
| Subdivision Type2: | District |
| Unit Pref: | Imperial |
| Population As Of: | 1998 |
| Timezone: | CET |
| Utc Offset: | +1 |
Bou Ismaïl (بو إسماعيل) is a city in Bou Ismaïl District, Tipasa Province, Algeria. In 2008 it had a population of 40,984.[1] Its French colonial name was Castiglione.