| Kapıdağ Peninsula | |
| Native Name: | Kapıdağ Yarımadası |
| Location: | Mediterranean Sea |
| Coordinates: | 36.6212°N 28.8548°W |
| Country: | Turkey |
| Country Admin Divisions Title: | Region |
| Country Admin Divisions: | Mediterranean |
| Country Admin Divisions Title 1: | Provinces |
| Country Admin Divisions 1: | Muğla |
Kapıdağ Peninsula (Turkish: Kapıdağ Yarımadası) is a peninsula in southwestern Anatolia extending into the Mediterranean Sea in Muğla Province, Turkey, terminating in Cape Kurdoğlu. The peninsula forms the Gulf of Fethiye on its east. The peninsula was the site of the ancient town of Lydae.