Simeonovgrad (Bulgarian: Симеоновград, "town of Simeon") is a town in southern Bulgaria, located in Haskovo Province on both banks of the Maritsa River. Three bridges connect the town's two parts. It is the administrative centre of the homonymous Simeonovgrad Municipality. As of December 2009, the town has a population of 7,049 inhabitants.

Near Simeonovgrad lie the ruins of the Ancient Roman and Byzantine fortress of Constantia from the Late Antiquity (4th century AD), which developed into one of the large towns of Northern Thrace until the beginning of the 13th century.

The dominant religion is Eastern Orthodox Christianity. The town has two churches, the Church of the Most Holy Mother of God in the town centre and the Church of St Nicholas the Thaumaturge in the Zlati dol quarter.

The town's historical names were Tarnovo–Seymen and "Seymen", who is a Turkish brave man from Western Anatolia. During the Socialist period, the town was named "Maritza", for the river on which it is placed.

Simeonovgrad is also the seat of Simeonovgrad municipality (part of Haskovo Province), which includes the following 8 villages: