Sitalkes (reigned 431-424 bc) was one of the great kings of the Thracian Odrysian state. He was the son of Teres, and on the sudden death of his father in 431 bc Sitalkes succeeded to the throne. Sitalkes increased his kingdom by successful wars, and soon the Odrysian state of Thrace comprised the whole territory from Abdera in the south to the mouths of the Danube in the north, and from Byzantium in the east to the sources of the Strymon in the west.

At the commencement of the Peloponnesian war he entered into alliance with the Athenians, and in bc 429 he invaded Macedon (then ruled by Perdiccas II) with a vast army that included independent Thracian tribes (such as the Dii) and Paeonian tribes (Agrianes, Laeaeans), but was obliged to retire through failure of provisions, and was killed in bc 424 by the Thracian Triballi.

Sitalkes was succeeded to the Odrysian throne by Seuthes I.