Family name Johae (Johae 
) , around the world, is a very rare last name. The last name Johae is habitual in Germany, where it is a very rare surname, France, and the United Kingdom, where it is an extremely rare surname. Not in comparison with a country's population, it is commonest in Germany, France, and the United States. Very seldom, Johae is the forename as well as the last name.