Carloforte is only accessible by ferry. Two routes serve the island:
- Portovesme to Carloforte — the more frequent service, about 30–40 minutes. Portovesme is on the southwest coast of Sardinia near Carbonia.
- Calasetta to Carloforte — this route crosses the sheltered channel between Isola di Sant'Antioco and Isola di San Pietro, making it the better option in rough weather when the Portovesme route can be choppy.
Both routes carry cars as well as passengers. Car ferry bookings are recommended in summer. Delcomar is the main operator.