Bahram I (also spelled Wahram I or Warahran I; 𐭥𐭫𐭧𐭫𐭠𐭭) was the fourth Sasanian King of Kings of Iran from 271 to 274. He was the eldest son of Shapur I (240-270) and succeeded his brother Hormizd I (270-271), who had reigned for a year.
Bahram I's reign marked the end of the Sasanian tolerance towards Manichaeism, and in 274, with the support of the influential Zoroastrian priest Kartir, he had Mani imprisoned and executed. Bahram I's reign was largely uneventful. He was succeeded by his son Bahram II.
The theophoric name "Bahram" (بهرام یکم) is the New Persian form of the Middle Persian Warahrān (also spelled Wahrām), which is derived from the Old Iranian Vṛθragna. The Avestan equivalent was Verethragna, the name of the old Iranian god of victory, whilst the Parthian version was *Warθagn. The name is transliterated in Greek as Baranes, whilst the Armenian transliteration is Vahagn/Vrām. The name is attested in Georgian as Baram and Latin as Vararanes.