Tattenai (or Tatnai or Sisinnes; Hebrew: תַּתְּנַי Tattǝnay; Akkadian: 𒋫𒀜𒄨𒉡 Tâttannu or 𒋺𒄨𒉡 Tattannu) was a Biblical character and a Persian governor of the province west of the Euphrates River during the time of Zerubbabel and the reign of Darius I.