The Taira clan (平氏, Taira or Hira or Hei-shi^?) was a major Japanese clan of samurai in historical Japan.

In reference to Japanese history, along with Minamoto, Taira was a hereditary clan name bestowed by the emperors of the Heian Period to certain ex-members of the imperial family when they became subjects. The Taira clan is often referred to as Heishi (平氏^?, literally "Taira clan") or Heike (平家^?, literally "House of Taira"), using the character's Chinese reading hei.

Offshoots of the imperial dynasty, some grandsons of Emperor Kammu were first given the name Taira in 825 or later. Afterwards, descendants of Emperor Nimmyō, Emperor Montoku, and Emperor Kōkō were also given the surname. The specific hereditary lines from these emperors are referred to by the emperor's posthumous name followed by Heishi. i.e. Kammu Heishi.

The Taira were one of the four important clans that dominated Japanese politics during the Heian period (794-1185) - the others were the Fujiwara, the Tachibana and the Minamoto.