The All-Russian Democratic Conference (Democratic Conference) was a meeting of representatives of political parties and public organizations, held in Petrograd from September 27 to October 5, 1917. The outcome of the meeting was the creation of the Pre-Parliament.

The decision to convene a Democratic Conference, as opposed to the Moscow State Conference, was taken at a joint meeting of the Central Executive Committee of the Soviets of Workers' and Soldiers' Deputies and the executive committee of the All-Russian Council of Peasant Deputies on September 3, 1917. The immediate impetus was the Rebellion of Lavr Kornilov and the collapse of the next government coalition, provoked by him; in a telegram inviting representatives of parties and public organizations to take part in the meeting, signed by the chairmen of the Central Executive Committees Nikolay Chkheidze and Nikolai Avksentiev, it was said about "convening in Petrograd a congress of the entire organized Democracy of Russia to create a strong revolutionary power capable of uniting all revolutionary Russia to repulse external enemies and to suppress all attempts at conquered freedom". The opening of the meeting was scheduled for September 25, 1917.

The purpose of the meeting, one of its initiators, Fedor Dan, a member of the Central Executive Committee of the Council of Workers' and Soldiers' Deputies, explained as follows:

The idea of the Democratic Conference, convened after and in contrast to the National Conference in Moscow, was connected in the minds of its initiators with the consciousness of the need to form a homogeneous democratic government to replace a coalition government, a government with representatives of the bourgeoisie, which clearly began to fall apart after the notorious June offensive at the front and received a mortal wound in days of the Kornilov uprising. I do not pretend to say that all the leading members of the Central Executive Committee looked at the tasks of the Democratic Conference just like that, but I can categorically say that the most prominent members of the Central Executive Committee looked at them that way, and that was exactly my own point of view... The idea that guided us in convening the Democratic Conference was to try to create a democratic government based not only on those elements of revolutionary democracy, in the close sense of the word, which were concentrated in the Soviets, but also on those that had a solid base in cooperatives and local governments (city councils and zemstvos)... We were encouraged by the successes in rapprochement with this "non-Soviet" democracy, achieved at the State Conference in Moscow: as you know, after long disputes and wrangles, both cooperators and democratic representatives of zemstvos and cities signed a political and economic platform drawn up by the delegation of the Central Executive Committee and announced by Chkheidze on behalf of all democracy at a meeting of the Conference on August 14.

Indeed, not everyone understood the purpose of the Conference as Dan did: his party comrade, Irakli Tsereteli, at the Conference itself, argued that a "homogeneous democratic government" would not be viable. He also formulated another task for this forum: to create a representative body to which the Provisional Government would report until the Constituent Assembly.

The Tsereteli initiative was viewed by the right and the left very differently. The leader of the Party of Constitutional Democrats Pavel Milyukov wrote: "In this way, the Democratic Conference became higher than the government, which was made responsible to it. But this was precisely the very thing that the Bolsheviks strove for when they wanted to transfer "all power to the soviets". Tsereteli's idea was essentially a complete surrender to the plans of Lenin and Trotsky". "Quite the opposite", protested Leon Trotsky, "Tsereteli's idea was to paralyze the Bolshevik struggle for Soviet power. The Compromisers created a new base for themselves, trying to crush the Soviets with an artificial combination of all kinds of organizations. Democrats distributed their votes at their discretion, guided by one concern: to secure an undeniable majority".

The meeting, scheduled for September 25, opened at the Alexandrinsky Theater late, on September 27, 1917, when more than 1,000 delegates gathered. In total, according to Izvestia, 1582 delegates participated in the Democratic Conference, including: from the Soviets of Workers' and Soldiers' Deputies – 230, from the Soviets of Peasants' Deputies – 230, from trade unions – 100, from city governments – 300, from zemstvos – 200, from organizations of the army and navy – 125, from general cooperation – 120, from national organizations – 60, from working cooperation – 38, from Cossack organizations – 35, from economic organizations – 33, from the Union of Railway Workers – 27, from commercial and industrial employees – 20, from zemstvo commissions – 20, from food committees – 17, from the Teachers' Union – 15, from the Postal and Telegraph Union – 12, from paramedics – 5 and 1–2 delegates from the Union of Women's Democratic Organizations and the Union of Crippled Warriors, etc. (Izvestia, 1917, September 8 and 10, 1917). Of the political parties, the Socialist Revolutionaries had the largest representation – 532 (Izvestia had not yet divided them into right and left), 172 were Mensheviks, 136 were Bolsheviks, 55 were Trudoviks (Representatives of the Labor Socialist Party), 23 were Ukrainian Social Revolutionaries, Bundists – 15, representatives of other national socialist parties – 28; another 400 delegates signed up as non-partisan (Izvestia, September 14 and 17, 1917).

Among the invited were also the Ministers of the Provisional Government (Alexei Nikitin, Alexander Verkhovsky, Dmitry Verderevsky, Kuzma Gvozdev) and members of the diplomatic corps from the Allied powers.