Antanas Tumėnas (13 May 1880 in Kurkliečiai, near Rokiškis – 8 February 1946 in Bachmanning, Austria) was a Lithuanian politician, teacher, professor of law, judge, Prime Minister of Lithuania in the 10th cabinet, Chairman of the Supreme Committee for the Liberation of Lithuania. He was a member of the Lithuanian Christian Democratic Party.
Tumėnas was elected to the Constituent Assembly of Lithuania and was appointed as chairman of the Constitutional Commission of Lithuania (1922).
Later he was a member of the 1st Seimas. He was the speaker of Seimas in 1923. He participated in creating the law system of the new republic. He was Minister of Justice in the 9th, 10th and 11th Cabinets of Lithuania.