Surname Gustr (Gust 
, Gustr, Gustur 
) , worldwide, is quite a common last name. The cognomen Gustr is habitual in Germany, where it is quite a rare surname, Luxembourg, and the United States, where it is a rare surname. Measured by absolute frequency, it is the most numerous in the United States, Germany, and Malaysia. Also, Gustr is the forename as well as the last name.