The Socialist-Revolutionary Party (SRs) were a Russian political party active in the early Twentieth Century.

Their programme was in the democratic socialist mould and garnered much support amongst Russia's rural Peasantry who in particular supported their programme of land-socialisation as opposed to the Bolshevik programme of land-nationalisation. Their policy platform could be broadly described as left-wing, although more moderate than that of the Bolsheviks.

The Russian Revolution of February, 1917 brought the SRs a more prolific political role, with one of their members Alexander Fedorovich Kerensky joining the liberal government, eventually becoming the head of government.

In 1917 the SRs split between those who supported the Provisional Government, established after the February Revolution, and those who supported the Bolsheviks who favoured a communist revolution. Those who supported revolution became known as Left Socialist-Revolutionaries and in effect split from the main party.

The SRs faded after the Bolshevik takeover in October, 1917, although in the elections to the Constituent Assembly they proved to be the most popular party across the country, gaining some 40% of the popular vote as opposed to the Bolsheviks 25%. However, the Bolsheviks disbanded the Assembly and thereafter the SRs become of less political significance, although some left-SRs did become part of the government of the Soviet Union, although they resigned their posistions after the Treaty of Brest-Litovsk was signed. A few left-SRs joined the Communist Party.

Many SRs fought for the Greens in the Russian Civil War alongside Mensheviks and other banned moderate socialist elements. A SR tried to assassinate Lenin in response to their proscription.