The Denmark international, who played 101 times for his country, played in the Premier League for Sunderland, Aston Villa and Stoke, making more than 400 appearances for the three clubs.
Most recently with Melbourne City in Australia's A-League, the Fredericia-born player plans to stay in the country where he will take part in a 3,500-kilometre charity bike ride next year.
Sorensen made the announcement about his retirement on his Instagram account.
He wrote: "It's with great pride and a little bit of sadness, that I today officially announce my retirement from professional football.