Vieu-d'Izenave (, literally Vieu of Izenave; ) is a commune in the Ain department in eastern France.
Vieu-d'Izenave has an oceanic climate (Köppen climate classification Cfb). The average annual temperature in Vieu-d'Izenave is . The average annual rainfall is with November as the wettest month. The temperatures are highest on average in July, at around , and lowest in January, at around . The highest temperature ever recorded in Vieu-d'Izenave was on 31 July 2020; the coldest temperature ever recorded was on 7 February 2012.