By Agence France-Presse
Putin, who has ruled Russia for almost two decades, recorded his best ever election performance with more than 76 percent of the vote, but the opposition cried foul.
Monitors reported ballot stuffing and other cases of alleged fraud as the Kremlin pushed for a high turnout to give greater legitimacy to Putin's historic fourth term.
The Russian strongman ran against seven other candidates, but his most vocal critic Alexei Navalny was barred from the ballot for legal reasons and the final outcome was never in doubt.
"I see in this (result) the confidence and hope of our people," Putin said in an address to a crowd of supporters on a square next to the Kremlin after exit polls put him on track for a resounding victory.
"Our thoughts will turn to the future of our great country and the future of our children," said the man who is already Russia's longest-serving leader since Stalin.
About 107 million Russians were eligible to cast ballots and in its latest update on participation, three hours before polls closed in Moscow, the central election commission said turnout was at 60 percent.
Authorities used both the carrot and the stick to boost engagement in the polls.
Selfie competitions, giveaways, food festivals and children's entertainers were laid on at polling stations in a bid to create a festive atmosphere around the election.
But employees of state and private companies reported coming under pressure to vote, while students were threatened with problems in their exams or even expulsion if they did not take part, according to the independent Novaya Gazeta newspaper.
According to central election commission data with 90 percent of ballots counted, Putin took 76.4 percent of the vote, well ahead of his nearest competitor Communist Party candidate Pavel Grudinin who was on 12 percent.
Ultra-nationalist firebrand Vladimir Zhirinovsky took around 6 percent, former reality TV presenter Ksenia Sobchak was on 1.5 percent and other candidates were on less than a single percentage point each.
The election was held as Russia faces increasing isolation on the world stage over a spy poisoning in Britain and a fresh round of US sanctions just as it gears up for the football World Cup in the summer.
- 'Unprecedented violations' -
Navalny -- who called on his supporters to boycott the "fake" vote and sent more than 33,000 observers across the country to see how official turnout figures differed from those of monitors -- said there had been "unprecedented violations".
His lawyer Ivan Zhdanov said the actual national turnout at 1700 GMT, when polls closed in Moscow, was 55 percent, according to data collected by monitors.
Navalny's opposition movement and the non-governmental election monitor Golos reported ballot stuffing, repeat voting and Putin supporters being bussed into polling stations en masse.
One election commission worker in the republic of Dagestan, which traditionally registers extremely high official turnout figures, told AFP around 50 men entered the station where he was working and physically assaulted an observer before stuffing a ballot box.
But the electoral commission dismissed most concerns, saying monitors sometimes misinterpret what they see.
Runner-up Grudinin said the elections had been "dishonest" in comments carried by news agencies following early results.
- Putin 'a hero' -
Since first being elected president in 2000, Putin has stamped his total authority on the world's biggest country, muzzling opposition, putting television under state control and reasserting Moscow's standing abroad.
The 65-year-old former KGB officer used an otherwise lacklustre presidential campaign to emphasise Russia's role as a major world power, boasting of its "invincible" new nuclear weapons in a pre-election speech.
Most people who spoke to AFP on Sunday said they voted for Putin, praising him for restoring stability and national pride after the humiliating collapse of the Soviet Union.
"Of course I'm for Putin, he's a leader," said Olga Matyunina, a 65-year-old retired economist.
"After he brought Crimea back, he became a hero to me."
Sunday marked four years since Putin signed a treaty declaring Crimea to be part of Russia in a move that triggered a pro-Kremlin insurgency in east Ukraine, a conflict that has claimed more than 10,000 lives.
- Voting in space -
Ahead of the vote, a new crisis broke out with the West as Britain implicated Putin in the poisoning of former double agent Sergei Skripal with a Soviet-designed nerve agent.
In response, London expelled 23 Russian diplomats, prompting a tit-for-tat move by Moscow. Also this week, Washington hit Russia with sanctions for trying to influence the 2016 US election.
After his victory, Putin dismissed claims Russia was behind the poisoning in Britain as "drivel, rubbish, nonsense" but said Moscow was ready to cooperate with London in the probe.
Putin's previous Kremlin term was marked by a crackdown on the opposition after huge protests, the Ukraine conflict, military intervention in Syria and the introduction of Western sanctions that contributed to a fall in living standards.
The president has said he will use his fourth term to address a litany of domestic problems including widespread poverty and poor healthcare.
"Another six years of slavery," said a piece of paper made up to look like a ballot which was spotted on a Moscow street -- in an apparent reference to Putin's next term.
Election officials flew to far-flung regions to collect votes from indigenous herders, while cosmonaut Anton Shkaplerov -- the only Russian currently aboard the International Space Station -- cast his ballot by proxy.