Nicomedes II Epiphanes (Greek: Νικομήδης Β' ὁ Ἐπιφανής) was the king of Bithynia from 149 to c. 127 BC. He was fourth in descent from Nicomedes I. Nicomedes II was the son and successor of Prusias II and Apame IV. His parents were related as they were cousins.
He was so popular with the people that his father sent him to Rome to limit his influence. However in Rome, he also gained favor from the Roman Senate, forcing Prusias to send an emissary with secret orders to assassinate him. But the emissary revealed the plot, and persuaded the prince to rebel against his father.
Supported by Attalus II Philadelphus, king of Pergamon, he was completely successful, and ordered his father to be put to death at Nicomedia. During his long reign Nicomedes adhered steadily to the Roman alliance, and assisted them against Eumenes III of Pergamon. He was succeeded by his son Nicomedes III.
| Preceded by Prusias II |
King of Bithynia 149 BC – 127 BC |
Succeeded by Nicomedes III |