The Constitutionalist Party of Japan (リッケントウ; 立憲黨 Rikkentō) is a Japanese political party founded in 1920. The Constitutionalist Party is part of the National Front with the Nationalist Party of Japan since its formation.
The Constitutionalist Party was founded by the Japanese liberal democrats and national conservatives that sided with the Nationalists during the Japanese Civil War through the merger of the Reform Party, the Unity Party, the conservative wing of Liberal Party, and the Constitutional Government Association on April 5, 1920. Together with Christian People’s Party, the Constitutionalists representing the right-wing elements of National Front.
Although always gained a second highest number of seats in the elections of National Congress and State Council since 1947, the Constitutionalists considered by many is only a loyal and subordinate party for the stronger Nationalist Party rather than playing a part as an effective opposition party.