Aigai or Aegae may refer to:
- Aigai, Macedonia, first capital of Macedon
- Aegae (Achaea), ancient settlement near present Aigeira, in Achaea
- Aegae (Euboea), ancient town in Euboea, near which a sanctuary of Aegean Poseidon was built upon a hill
- Aege, town in Pallene, Chalcidice
- Aigai (Aeolis), ancient city of the Aeolian dodecapolis, near the modern city Aliağa, northwestern Turkey
Aigai, also Aigaiai ( or ; or ; or ) was an ancient Greek, later Roman (Ægæ, Aegae), city and bishopric in Aeolis. Aegae is mentioned by both Herodotus and Strabo as being a member of the Aeolian dodecapolis. It was also an important sanctuary of Apollo. Aigai had its brightest period under the Attalid dynasty, which ruled from nearby Pergamon in the 3rd and 2nd century BC.
The remains of the city are located near the modern village of Yuntdağı Köseler in Manisa Province, Turkey. The archaeological site is situated at a rather high altitude almost on top of Mount Gün (Dağı), part of the mountain chain of Yunt (Dağları).