Hjarnø
| Geography | |
|---|---|
| Location | Kattegat | 
| Coordinates | 55°49′30″N 10°5′0″E / 55.82500°N 10.08333°E | 
| Area | 3.2 km2 (1.2 sq mi) | 
| Administration | |
| Region | Central Denmark Region | 
| Municipality | Hedensted Municipality | 
| Demographics | |
| Population | 104 (2013) | 
Hjarnø is a small Danish island at the mouth of Horsens Fjord on the east coast of Jutland in Hedensted Municipality.