| Alcetas I | |
|---|---|
| King of Epirus | |
| Reign | 390 - 370 BC |
| Predecessor | Tharrhypas |
| Successor | Neoptolemus I of Epirus |
| Issue | Neoptolemus I of Epirus Arybbas |
| House | Aeacidae |
| Father | Tharrhypas |
| Religion | Ancient Greek religion |
Alcetas I (Greek: Ἀλκέτας) (390/385 – 370 BC) was a king of Epirus. He was the son of Tharrhypas. Alcetas was the great-grandfather of Pyrrhus of Epirus and Alexander the Great.