Michael, 45, touring North America for the first time in 17 years, told fans during a concert at New York City's Madison Square Garden that "I know you guys all need a change."
He admitted he doesn't know what kind of change Obama would bring if elected, saying that after "months of watching CNN" he still does not know what Obama or Clinton stand for. But he went on to say that the Illinois and New York senators would make "the strongest team" for the Democratic ticket.
Michael rose to fame in the early 1980s as one-half of the singing duo Wham!, which scored the huge hit single "Wake Me Up Before You Go Go."
But it was as a solo artist with 1987's "Faith" that he broke into the ranks of pop superstars and enjoyed massive hits such as the song "I Want Your Sex."
Michael, whose given name is Georgios Kyriacos Panayiotou, ran into trouble with police in Beverly Hills, California, in 1998 when he was arrested for engaging in a lewd act in a public restroom.
He pleaded no-contest to the charge, was fined a small amount and ordered to perform community service. The incident forced the singer to openly disclose his homosexuality, and his relationship with American Kenny Goss.
During Monday's show he dedicated his song "Amazing" to Goss, who was in the audience, and commented at one point that gay marriage should be legal in New York. He also played hits including "Fast Love," "Father Figure" and "Freedom."
He has been regularly featured in Britain's tabloid newspapers for his behavior. In June 2007 he was banned from driving for two years and sentenced to 100 hours' community service after admitting driving under the influence of drugs.
He also infuriated mental health charities in 2006 by smoking marijuana during a television interview and saying "This stuff keeps me sane and happy."
Reuters/Nielsen
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