Mihkel Klaassen

{{Short description|Estonian lawyer}}

Mihkel Klaassen (24 February 1880 – 7 March 1952) was a justice of the Supreme Court of Estonia since 1924.

Klaassen was a member of the Electoral Committee ({{langx|et|Vabariigi Presidendi Asetäitja Valimiskogu}}) that decided the Soviet-era appointment of Johannes Vares as prime minister by Konstantin Päts had been illegal and stated, that Jüri Uluots is prime minister acting as President of the Estonian Republic on April 20, 1944.Lauri Mälksoo, Professor Uluots, the Estonian Government in Exile and the Continuity of the Republic of Estonia in International Law, Nordic Journal of International Law, Volume 69, Number 3 / March, 2000

He was the father of Professor Olaf-Mihkel Klaassen of Tartu University.