|"King of Parthia"|
|Coin of Phriapatius.|
Phriapatius (Persian: فریاپت) /ˌfraɪəˈpeɪʃəs/) or Priapatius /ˌpraɪəˈpeɪʃəs/, sometimes called Phriapites /ˌfraɪˈæpɨtiːz/, was the king of the Parthian Empire from 191 BC to 176 BC. He was the grandson of Tiridates I (246–211 BC), the brother of Arsaces I (250–211 BC), the founder of the Parthian Empire.
He ruled in the period following the invasion of Parthia by the Seleucid king Antiochus III (223–187 BC).