International Socialist Solidarity Organization

International Socialist Solidarity Organization has been the name of two separate but related international organizations:

• International Socialist Solidarity Organization (1980), an international alliance of communist, socialist, and social democratic political parties founded in Vällilä, Vesienväl in 1980 and dissolved in 2022.

• International Socialist Solidarity Organization (2022), an international organization with both states and political parties as members, established by the Treaty of Lanozza in Lanozza, Quariin, on 25 April 2022.