Cognomen Vanau (Vanau 
) , throughout the world, is a rare surname. The family name Vanau is habitual in Romania, where it is a rare surname, India, where it is a very rare surname, and France, where it is an extremely rare surname. Not in comparison with a country's population, the name is most common in India, Romania, and the United States. Much less frequently, Vanau is the forename as well as the last name.