In 1904 the Social Democratic Party was formed by Persian emigrants in Transcaucasia with the help of local revolutionaries, maintaining close ties to the Russian Social Democratic Labour Party and Hemmat Party. or 1905 It was the first Iranian socialist organization. The party created its own mélange of European socialism and indigenous ideas and upheld liberalism and nationalism. It maintained some religious beliefs while being critical of the conservative ulama and embracing separation of church and state. It was founded by Haydar Khan Amo-oghli and led by Nariman Narimanov.
During the constitutional period, the Unified Socialist and Social Reformers Party were both socialist political parties in Persia. The Social Reformers Party was considered to follow a moderate line in comparison to the Democrat Party and the Social Democratic Party's economic platform, but opposed the landlords likewise.
Founded in 1909 in Qajari Persia during the constitutional period, the Democrat Party was one of two major parliamentary parties at the time alongside its rival, the Moderate Socialists Party. The party had a social democrat ideology, initially was an offshoot of the Transcaucasia-based Social Democratic Party. It severed direct ties with Baku and dropped "Socialist" from the name in deference to the conservative public. Its ideology, however, remained heavily borrowed from the old party. It was largely composed of middle-class intellectuals and stood for the separation of church and state.
Founded in the 1900s, the Socialist Revolutionary Party, also known as Social-Revolutionaries, was a Persian revolutionary socialist party based in Baku, Caucasus. It was one of the most important parties established by the Persian emigrants in Transcaucasia during Qajar dynasty. The party published an Azerbaijani language newspaper twice a week, named Ekinçi ve Fe'le and edited by Hosayn Israfilbekov.
Originally established as the Justice Party in 1917, the Communist Party of Iran was an Iranian communist party founded by former Social Democratic Party's members who supported Baku-based Bolsheviks, the party participated in Third International in 1919 and was renamed to the Communist Party of Iran in 1920.