Battle of Orchomenus

Infobox Military Conflict
conflict=Battle of Orchomenus


caption=
partof=First Mithridatic War
date= 85 BC
place=Orchomenus, Beotia (modern Greece)
result=Roman victory
combatant1=Roman Republic
combatant2=Pontus
commander1=Sulla
commander2=Archelaus
strength1=15,000-16,000
strength2=75,000-80,000
casualties1=about 100
casualties2=heavy, suggested some 15,000

The Battle of Orchomenus was fought in 85 BC between Rome and the forces of Mithridates VI of Pontus. The Roman army was led by Lucius Cornelius Sulla, while Mithridates' army was led by Archelaus. The Roman force was victorious, and Archelaus later defected to Rome.

Archelaus, who had received reinforcements from Mithridates and from his Greek allies, again outnumbered Sulla by about the same margin as at Chaeronea. Sulla, contemptuous of his adversaries, but exercising judicious care in his plans and preparations, again used field fortifications to assist him in advancing against the sluggish foes, defeating by a decisive envelopment. Sulla now prepared to invade Asia.