Blasius Kozenn (Slovene: Blaž Kocen; 24 January 1821 in Hotunje, Lower Styria – 29 May 1871 in Hernals) was a Slovenian geographer and cartographer. He has occasionally been misidentified as Slovak. The name Kozenn was familiar to generations of former pupils in Austria-Hungary because Kozenn's school atlas was published in millions of copies in more than 100 editions and in many languages. It was one of the most commonly used atlases in the Austrian half of Austria-Hungary.