Boris Meissner (10 August 1915 Pskov, Russian Empire - 10 September 2003 Cologne, Germany) was a German lawyer and social scientist, specializing in Soviet studies, international law and Eastern European history and politics.
He then studied law in Tartu until he had to leave Estonia during the repatriation of Baltic Germans (Umsiedlung der Deutsch-Balten) in 1939.
From 1946 until 1953 he headed the Ostrecht (Eastern European law) desk at the Forschungsstelle für Völkerrecht und ausländisches öffentliches Recht of Hamburg University.
During his time at the Soviet desk, he was a member of the German delegation accompanying Konrad Adenauer on his visit to Moscow in September 1955 and the Four Power Conferences on Germany in Berlin (1954) and Geneva (1955; 1959).
In 1961 Meissner initiated the foundation of the Federal Institute for Eastern European and International Studies (Bundesinstitut für Ostwissenschaftliche und Internationale Studien).
At the same time he advised the Foreign Office on policy towards the East Bloc, and later served as director of its advisory committee from 1972 - 1982.