Navalny was detained by police ahead of a rally on Friday and could face up to a month in jail.
Police took Navalny into custody after he left his apartment with the intention of traveling to the rally in the provincial city of Nizhny Novgorod.
The event was due to start at 6:00 p.m. (1500 GMT) but Moscow police said Navalny was detained “over multiple calls to participate in an unauthorized public event.”
The 41-year-old was charged with repeatedly violating a law on organizing public meetings, punishable by up to 30 days in jail.
Navalny, who is married with two children, has been arrested numerous times before by Russian authorities over various charges including embezzlement and fraud.
One of his lawyers, Olga Mikhailova, told AFP that Navalny had been kept all day at the police station without a written statement outlining any reasons for detention.
Navalny claimed he did not receive any official explanation.
“I am sitting in a reception room and looking at a portrait of Putin,” he said on Twitter.
Navalny has gained many online followers, who are mostly young people, via social media. He says state-owned corporations are corrupt.
Navalny made headlines in late March after he was briefly arrested along with some 1,000 people for protests that came following his allegations about corruption in the government. He made the headlines again in April when an attacker doused his face with a green antiseptic liquid.
The opposition leader and outspoken critic of Russian President Vladimir Putin, shown above, has announced that he would run for the presidency in the 2018 election, describing his presidential bid as a “clash of ideas” with the old establishment.