| Karlonisi | |
| Native Name: | Καρλονήσι |
| Native Name Lang: | el |
| Coordinates: | 38.475°N 21.043°W |
| Map: | Greece |
| Location: | Ionian Sea |
| Archipelago: | Echinades |
| Area Km2: | 0.719 |
| Elevation M: | 77 |
| Country: | Greece |
| Country Admin Divisions Title: | Region |
| Country Admin Divisions: | Ionian Islands |
| Country Admin Divisions Title 1: | Regional unit |
| Country Admin Divisions Title 2: | Municipality |
| Country Admin Divisions 2: | Ithaca |
| Population: | 0 |
| Population As Of: | 2011 |
Karlonisi (Greek, Modern (1453-);: Καρλονήσι) is an island of the Echinades (Drakoneres subgroup), among the Ionian Islands group of Greece. It has an average elevation of .[1] It is administered by the municipality of Ithaca and is situated 30km (20miles) east of the island., it had no resident population.[2]