Janko Pleterski (1 February 1923 – 8 June 2018) was a Slovenian historian, politician and diplomat.
Pleterski was born on 1 February 1923 in Maribor, Slovenia, then part of the Kingdom of Serbs, Croats and Slovenes.
In August 1941, he was arrested by the Fascist authorities of the Italian-occupied Province of Ljubljana and imprisoned in Alessandria, Italy.
After the end of World War II, he worked at the Yugoslav foreign ministry in Belgrade as an expert on border issues with Italy and Austria.
[1] In 1953, Pleterski became a researcher at the Institute for Ethnic Studies in Ljubljana.