Vologases V of Parthia (Parthian: Walagash, Persian: بلاش‎, Balāsh), known in Armenian sources as Vologases II (Armenian: Վաղարշ, Vagharsh), was king of Arsacid Armenia from to 180 to 191, and king of the Parthian Empire from 191 to 208. He was the son of Vologases IV (147–191).

During his early life, he became the ruler of Armenia, succeeding Sohaemus. During his rule in Armenia, he managed in 189 to impose his son Rev I (whose mother was the sister of the Pharnavazid ruler Amazasp) on the Iberian throne. Vologases, after the death of his father, ascended the Parthian throne, and appointed his son Khosrov I as the ruler of Armenia. Vologases'' succession, however, was not uncontested; a rival King Osroes II (190) had already set himself up in Media before the death of the previous ruler, but Vologases V appears to have quickly put him down.

Vologases V was attacked by the Roman emperor Septimius Severus (193–211) in 195. Severus advanced into Mesopotamia, occupied Nisibis and plundered the Parthian capital Ctesiphon in 199, capturing many Parthians and selling them into slavery. He attempted in vain to conquer the Arabic fortress at Hatra. In 202, peace was restored with the Roman Empire in effective control the whole of Mesopotamia.

Vologases V later died in 208, and was succeeded by his elder son Vologases VI (208–228), but a younger son Artabanus V (216–224) rebelled and a civil war ensued.