“It was found that these organizations not only disseminated information that incited hatred and enmity against government officials, but also committed extremist actions,” a spokesman for the prosecutors, Alexei Zhafyarov, said outside the court.
A statement by the Moscow City Court after the 10-hour session said Navalny’s regional network offices and his anti-corruption organisation had been banned with immediate effect.
Navalny’s Anti-Corruption Foundation (FBK) has pressured the Kremlin in recent years by publishing investigations into high-level corruption among the political elite.
Those probes have in turn spurred massive street demonstrations.
His network of regional offices has also promoted the 45-year-opposition leader’s smart voting campaign, which encourages voters to cast ballots for candidates in elections most likely to unseat Kremlin-friendly incumbants.
The ruling Wednesday comes ahead of parliamentary elections in September, in which the deeply unpopular ruling United Russia party is expected to struggle.
Navalny, Putin’s most outspoken critic at home, survived a near-fatal nerve agent attack last summer that he blames on the Kremlin, a claim the administration denies.
Lawyers representing Navalny’s organisation said Wednesday they had been given 10 days to appeal the ruling, which they said in a statement online they would certainly do.