The former US president, who ordered the invasion of Iraq in 2003, made the blunder, branded "history's greatest Freudian slip", at an event on Wednesday.
George W Bush has accidentally condemned the "unjustified and brutal invasion of Iraq", an operation he ordered himself in 2003.
The former US president, 75, quickly corrected himself to say he had meant to refer to Vladimir Putin's invasion of Ukraine.
Mr Bush told the audience in the city of Dallas: "Russian elections are rigged, political opponents are imprisoned or otherwise eliminated from participating in the electoral process.
"The result is an absence of checks and balances in Russia, and the decision of one man to launch a wholly unjustified and brutal invasion of Iraq."
He then corrected himself and shook his head.
"I mean, of Ukraine," he said, before jokingly blaming the blunder on his age, muttering "I'm 75" as the audience burst into laughter.
Footage of the mishap has been watched more than 10 million times on Twitter after it was shared by Michael Williams, a reporter from Dallas News who was at the event.
Social media users described the error as "history's greatest Freudian slip".
Many have also criticised the former president for appearing to make light of the conflict in 2003.
Mr Bush was at the helm when the US led a devastating invasion of Iraq over claims of weapons of mass destruction that were never found.
which ofc doesn't imply that putin isn't a war criminal, i'm focusing on the part that war criminals are calling out another war criminal 
