Surname Tiagun (Tiagun 
, Тягун 
) , around the world, is a rare family name. The surname Tiagun is habitual in Ukraine, where it is quite a rare surname, Lithuania, where it is a rare surname, and Russia. Measured by absolute frequency, the name is most common in Ukraine, Russia, and Kazakhstan. Much less frequently, Tiagun is the forename as well as the last name.