Develtos (Greek: Δεβελτός, Δηβελτός, Δεουελτòς, Δεούελτος, Διβηλτóς) or Deultum was an ancient city and bishopric in Thrace. It was located at the mouth of the River Sredetska on the west coast of Lake Mandrensko, previously part of the Gulf of Burgas, and near the modern village of Debelt.
