He takes on President Vladimir Putin with the apparent fearlessness of someone with nothing to lose - but that's not the case.
The 44-year-old is a husband and father-of-two with half his life still ahead of him. Most people would opt for a quiet life rather than take on the intimidating modern equivalent of a tsar who has been the power in the land for two decades.
A Moscow court has sentenced Navalny to more than 2 1/2 years in prison after deciding that he violated the terms of his probation stemming from a 2014 embezzlement conviction that Navalny said was "fabricated".
The alleged violation occurred as Navalny spent five months recovering in Germany after nearly dying when he was poisoned and evacuated to Berlin in a coma.
Labs in western Europe confirmed the substance as Novichok, a nerve agent developed by the Soviet Union. Bellingcat, an investigative website, found that Navalny had been followed by security agents for years. Navalny discovered that agents applied the nerve agent to his underwear during a hotel operation.
He chose to return to Russia, knowing that he would be locked up.
He took the opportunity to lay into Putin in court.
"I participated in the investigation of my own poisoning, and we proved, in fact, that Putin, using Russia's Federal Security Service, was responsible for this attempted murder. And that's driving this thieving little man in his bunker out of his mind...
"He's never participated in any debates or campaigned in an election. Murder is the only way he knows how to fight. He'll go down in history as nothing but a poisoner ... Vladimir the Underpants Poisoner...
"Locking me up isn't difficult. What matters most is why this is happening. This is happening to intimidate large numbers of people. They're imprisoning one person to frighten millions.
"This isn't a demonstration of strength — it's a show of weakness. You can't lock up millions and hundreds of thousands of people. I hope very much that people will realise this. And they will. Because you can't lock up the whole country."
Long-time eastern Europe correspondent for the Guardian, Shaun Walker, tweeted: "Sending Navalny to prison for the long haul has to up there with Beslan, jailing [Mikhail] Khodorkovsky, war with Georgia and the annexation of Crimea in terms of major milestones of the Putin era".
The Government has cranked up efforts to squash the protests and no doubt hopes that a lengthy absence of the movement's figurehead will cause its momentum to ebb. Putin has the state security apparatus at hand.
The move puts Navalny out of action before the next presidential election in early 2024. A new study showing very good results for the Russian Covid-19 vaccine suddenly comes in handy for Putin's dealings with other countries.
Even so the regime has had to scramble in a way it is not used to. Navalny and his team have been able to speak to public discontent. They have at least temporarily wrested control of the political agenda and tried to undercut the idea of Putin the Strongman.
Navalny was able to highlight inequality, referring in court to "20 million people living below the poverty line" and "tens of millions living without the slightest prospects for the future". He added: "The only thing growing is the number of billionaires".
And then there's the power of his stunning example and a glimpse of a different way forward.
