Cognomen ทุ่น (Thun 
, Buoy 
, ทุ่น) , all around the world, is a common last name. The last name ทุ่น is characteristic of Myanmar, where it is quite a common surname, Norway, where it is quite a rare surname, and Sweden. Measured by absolute frequency, it is the most numerous in Myanmar, Germany, and the United States. Also, ทุ่น is the forename as well as the last name.