The Estonian Sovereignty Declaration (Estonian: suvernsusdeklaratsioon), fully: Declaration on the Sovereignty of the Estonian SSR (Deklaratsioon Eesti NSV suvernsusest), was issued on November 16, 1988 during the Singing Revolution in Soviet Estonia. The declaration asserted Estonia's sovereignty and the supremacy of the Estonian laws over the laws of the Soviet Union. Estonia's parliament also laid claim to the republic's natural resources: land, inland waters, forests, mineral deposits and to the means of industrial production, agriculture, construction, state banks, transportation, municipal services, etc. in the territory of Estonia's borders. November 16 is now celebrated annually as the "Day of Declaration of Sovereignty" (Suvernsuse deklareerimise pev).

The Supreme Soviet (Russian: Верховный Совет, romanized: Verkhovny Sovet, lit. 'Supreme Council') was the common name for the legislative bodies (parliaments) of the Soviet socialist republics (SSR) in the Union of Soviet Socialist Republics (USSR). These soviets were modeled after the Supreme Soviet of the USSR, established in 1938, and were nearly identical.State-approved delegates to the Supreme Soviets were periodically elected unopposed in show elections. The first free or semi-free elections took place during perestroika in late 1980s, in which Supreme Soviets themselves were no longer directly elected. Instead, Supreme Soviets were appointed by directly-elected Congresses of People's Deputies based somewhat on the Congresses of Soviets that preceded the Supreme Soviets. The soviets until then were largely rubber-stamp institutions, approving decisions handed to them by the Communist Party of the USSR or of each SSR.The soviets met infrequently (often only twice a year for only several days) and elected the Presidium of the Supreme Soviet, a permanent body, to act on their behalf while the soviet was not in session. Under the 1936 and 1977 Soviet Constitutions, the Presidium of a Supreme Soviet served as the collective head of state of its republic. The Supreme Soviets also elected Councils of Ministers (Councils of People's Commissars before 1946), which were executive bodies.

After the dissolution of the USSR in late December 1991, most of these soviets remained the legislatures of independent countries until Armenia, Azerbaijan and Kazakhstan abandoned the system in 1995.