The National Party (National Partei) was one of the three major political parties in a German state known as the Principality of Lippe-Detmold. Founded in 1836, it was a minority party and held just over one-fifth of the seats in the upper house of the local Landtag. The party fiercely advocated for the independence and sovereignty of Lippe. During the dispute between the two branches of the House of Lippe in the 1890s, the National Party backed Count Ernst of the Lippe-Biesterfeld line, against the Conservative-supported Prince Adolf, of the Lippe-Schaumburg line.
The National Party was dissolved in 1871, when Lippe became a state of the German Empire. Some of its former members became members of underground nationalist groups that sought to restore the country's independence.