Family name Letnan (Letnan 
, Lieutenant 
, Luitenant) , in the world, is a rare cognomen. The family name Letnan is habitual in Western Europe, particularly Luxembourg, where it is quite a rare surname, Belgium, and Germany, where it is a very rare surname. In absolute terms, this name is the most popular in Belgium, Indonesia, and Germany. Also, Letnan is the forename as well as the last name.