The Conservative Party (Konservative Partei) was one of the three major political parties in a German state known as the Duchy of Nassau. Founded in 1836, it was the dominant party in the duchy for many years and consistently held the majority of the seats in the upper house.
When Nassau became a state of the German Empire in 1871, the party was reformed as the local branch of the Conservative Party of Germany. It was completely dissolved in 1918 after World War I after the abolition of German monarchies and the disbandment of the Conservative Party.