In all the world, Katje (Katje 
) is a rare mostly feminine, but infrequently masculine first name. The given name Katje is habitual in Belgium, where it is a rare girly name, Indonesia, where it is a very rare epicene name, and South Africa. Not in comparison with a country's population, the name is most common in Indonesia, the United States, and Belgium. Likewise, Katje is the last name as well as the forename.