Two television exit polls, released after voting ended at 1700 GMT, forecast the former KGB spy would win 59.3% and 58.3% of the votes, enough to make a run-off against the second-placed candidate unnecessary.
His nearest rival, communist Gennady Zyuganov, fell short of 20% in both polls.
Putin’s opponents said voting in many parts of the vast country was skewed to help him return to the presidency after four years as prime minister and vowed to step up the biggest protests since he rose to power 12 years ago.
But although they portray him as an authoritarian ruler who is out of touch, his victory had not been in any doubt.
The main challenge for Putin, credited by many Russians with rebuilding the country’s image and overseeing an economic boom, was to win outright in the first round.
“I think the elections will be legitimate, fair, and Putin will win in the first round, unless the court rules otherwise,” Putin’s spokesman, Dmitry Peskov, was shown saying on Internet and cable television channel TV Dozhd before voting ended.
Putin was likely to portray the victory as strong backing against the opposition protesters, although he has promised not to crack down on them.
He is also expected to return to the Kremlin with tough fighting talk against the West, a trademark of his first presidency and election campaign.
Some voters expressed anger at being offered no real choice in a vote pitting Putin against four others — communist Zyuganov, nationalist Vladimir Zhirinovsky, ex-parliamentary speaker Sergei Mironov and billionaire Mikhail Prokhorov.
Others said Putin, 59, who has portrayed himself as a man of action and guardian of stability, was the tough national leader the world’s biggest country and energy producer needed.