Vlado Chernozemski (19 October 1897 – 9 October 1934), born Velichko Dimitrov Kerin (Bulgarian: Величко Димитров Керин), was a Bulgarian revolutionary, who later became the most dangerous terrorist in Europe.
Chernozemski began his revolutionary activities in 1922, when he joined the Internal Macedonian Revolutionary Organization (IMRO). Soon after, he became an assassin for the IMRO. He killed two notable Bulgarian politicians, the communist, Dimo Hadzhidimov, and IMRO member, Naum Tomalevski. Both times he was sentenced to death, but he escaped from the first punishment and was released from the second. After he was released from prison in 1932, he became an instructor for the Ustaše. He trained a group of Ustaše to assassinate Alexander of Yugoslavia, but eventually Chernozemski himself killed Alexander on 9 October 1934. He was then beaten by the French police and spectators, and died the same day.