Sosism (Spanish: Sosismo) was a short-lived corporatist political movement in Uruguay, led by Julio María Sosa.

The movement was one of the three Colorado factions that opposed José Batlle y Ordóñez and tried to realign the party to the right-wing position along with Riverism and Vierism.

Sosists ran for the elections under the name of "Colorado Party for Tradition" (Spanish: Partido Colorado por la Tradición"). They directed the "La Razón" newspaper in Montevideo and "La Cruzada" in Treinta y Tres. The movement was also known as "Traditionalism" (Spanish: Tradicionalismo).

Sosism was deeply influenced by classical fascism, as Sosa was an outspoken supporter of the Italian corporate state.

Sosists were favourable to labour rights and criticised political opposers as reactionaries or conservatives. Despite their authoritarian positions, sosists saw themselves as defenders of "progress".

Sosa was in favour of a state corporatist regime, as well as of the abolition of the presidency and its replacement by a directorial system.

The sosist newspaper "La Razón" stated in 1928:

The general conviction is beginning to spread that Parliaments are only instruments of purely electoral interests, of bureaucratic designations, conducive to greed and the predominance of mediocrity (…) The system of government must be transformed. It is necessary to consider the country's main interests (...) The livestock industry, the agricultural industry, the manufacturing industries, the intellectual classes must have their own representation in the positions of authority. The Parliament must be an organ of useful energies and not of adventitious conveniences. All modern politics is economic policy. Economic factors dominate the world, in international relations and in relationships within every country.