ISAC
- Emil Isac
- I. Peltz
- Idol Star Athletics Championships
- Immune stimulating antibody conjugate
- Indian Space Research Organisation Satellite Centre
- Information Sharing and Analysis Center
- Institute for the Study of American Cultures
- Institute for the Study of Ancient Cultures
- Isaac (name)
- Isac (river)
- Isac Ludo
- Isac Silvestre
- Mihaiela Isac
- Vadul lui Isac