Shapur III (𐭱𐭧𐭯𐭥𐭧𐭥𐭩 ), was the Sasanian King of Kings (shahanshah) of Iran from 383 to 388. He was the son of Shapur II (309-379) and succeeded his uncle Ardashir II (379-383).
His reign was largely uneventful; to the west, the dispute over Armenia with the Romans continued, which was eventually settled through diplomacy, with the two empires agreeing to partition the area, with most of it remaining under Sasanian control. To the east, Shapur III lost control of the important mint city Kabul to the Alchon Huns.
He is notable for having a rock relief carved at Taq-e Bostan, depicting a scene of him along with his father. He was the penultimate monarch to have a rock relief carved, the last one being Khosrow II (590-628), who mimicked and magnified Shapur III's work. The king died in 388, after reigning for five years. He was crushed by the collapsing weight of his own tent, after some conspiring nobles had cut its ropes. His son Bahram IV succeeded him.