Chalcedon
- For the Ecumenical Council of 451, see Council of Chalcedon.

Bithynia as a province of the Roman Empire, 125 AD
Chalcedon (Χαλκηδών, sometimes transliterated as Chalkedon) was an ancient maritime town of Bithynia, in Asia Minor, almost directly opposite Byzantium, south of Scutari (modern Üsküdar). Today, in modern Turkish, Chalcedon is called Kadıköy and a district of Istanbul, Turkey.
Coordinates: 40°59′N 29°02′E / 40.983°N 29.033°E
Chalcedon Media
Funerary stele from the 1st century BC
Small silver jug from Chalcedon