- Iglesias
- Ilbono
- Illorai
- Ingurtosu
- Irgoli
- Is. Arenas
- Is Argiddas
- Is Aruttas
- Is Bangius
- Is Carillus
- Is Corrias
- Is Forredus
- Is Meddas
- Is Molas
- Is Morus
- Is Orrus
- Is Perrizzonis
- Is Pisus-Is Concias
- Is Punteddus
- Is Tanas
- Is Traias
- Is Urigus
- Iscra e Voes
- Isili
- Isola Barrettini
- Isola Cavalli
- Isola dei Cavoli
- Isola del Toro
- Isola delle Bisce
- Isola di Figarolo