Surname Ritiu (Ritiu 
) , throughout the world, is a very rare cognomen. The last name Ritiu is habitual in Romania, where it is a rare surname, Germany, where it is a very rare surname, and the United States, where it is an extremely rare surname. Measured by absolute frequency, this name is the most popular in Romania, Germany, and India. Likewise, Ritiu is the forename as well as the last name.