Tiridates I is King of Armenia beginning in CE 53 and the founder of the Arshakuni Dynasty, the Armenian line of the Arsacid Dynasty.

The dates of his birth and death are unknown.

His early reign is marked by a brief interruption towards the end of the year 54 and a much longer one from 58 to 63.

In an agreement to resolve the Roman-Parthian conflict in and over Armenia, Tiridates (who is the brother of Vologases I of Parthia) is crowned king of Armenia by the Roman emperor Nero in CE 66; in the future, the king of Armenia is to be a Parthian prince, but his appointment requires approval from the Romans.

Alhough this makes Armenia a client kingdom, various contemporary Roman sources think that Nero had de facto ceded Armenia to the Parthian Empire.

In addition to being a king, Tiridates is also a Zoroastrian priest and is accompanied by other magi on his journey to Rome in CE 66.

In the early 20th century, Franz Cumont speculated that Tiridates was instrumental in the development of Mithraism, which—in Cumont's view—was simply Romanized Zoroastrianism.

This "continuity" theory has since been questioned.

Tiridates is one of the principal characters in George Frideric Handel's opera Radamisto and Reinhard Keiser's opera Octavia.