Mr Putin's soaring approval rating is according to a survey by the state-run pollster VTsIOM published on Friday.
The conflict has displaced more than 10 million Ukrainians from their homes, killed or injured thousands, turned cities into rubble and led to sweeping Western sanctions that will push down Russian living standards.
VTsIOM said 78.9 per cent of respondents in its latest survey said they approved of Putin's actions, compared to 64.3 per cent in the last poll before the start of what Russia calls its "special military operation". The proportion who disapproved of his actions fell to 12.9 per cent from 24.4 per cent.
Ukraine and Western leaders have condemned Russia's military campaign as unprovoked aggression. The Kremlin says it had to demilitarise and "denazify" Ukraine to protect Russian-speakers and pre-empt a threat from the Western NATO alliance.
VTsIOM's numbers were similar to those in a survey published on March 30 by the independent Levada Centre, in which the proportion of Russians saying they approved of Putin's actions rose to 83 per cent from 71 per cent in February.
Levada recorded a comparable surge in Putin's approval rating in 2014, when Russia seized Crimea from Ukraine and annexed it and Russian-speaking separatists took control of part of the Donbas region of eastern Ukraine with Moscow's support.
Ordinary Russians have little access to independent reporting on their country as almost all significant media outlets that diverge from government policy have been closed down in the last few years.
Since February 24, Moscow has further restricted access to foreign media and social media, and made it a criminal offence to publish reports about the armed forces that deviate from official statements.
VTsIOM said it surveys 1,600 people across Russia each day and its weekly polls are an average of responses from the previous seven days.
The poll published on Friday was gathered between March 28 and April 4, it said.
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