A false report had claimed that the wrestler and actor had died in an accident on the set of a movie in New Zealand.
Johnson, who turned 39 on Monday, tweeted: "I would love to meet the person who is starting rumours of my death - to show them how a dead foot feels up their ass."
He is the latest in a string of celebrities to have been the subject of a hoax death report.
Last December, Charlie Sheen laughed off stories claiming that he had died by saying that he was concerned the reports referred to ratings figures for Two and a Half Men.
However, Bill Cosby used Twitter to express his distress at erroneous reports of his death. The claims arose after the phrase "Bill Cosby died" became a trending topic on the social networking site.
Eddie Murphy, Aretha Franklin and Avril Lavigne have also fallen victim to similar hoaxes in recent months.