Stating that hosts India were the favourites along with Australia, Flintoff backed England to go all the way to the title.
World T20, which began on March 8 with the qualifiers, ends in Kolkata on April 3.
Flintoff, who played 79 Tests, 141 ODIs and 7 T20Is for England, feels the Eoin Morgan-led side is not under pressure as the spotlight is not on them at this year's global tournament.
"I think England will win it, genuinely. I look at the team and the way in which they play," Flintoff told Lancashire Cricket TV.
"It's going to be tough in India. I think India are the favourites along with Australia but I think that will work in our advantage. I don't think anyone is expecting England to win and sometimes that's really nice.
"It frees you up and you can just play and go about your business. If you look at the side every department is covered," the 38-year-old Flintoff added.
England won the World T20 title in 2010, their only global trophy so far. They open campaign against West Indies on March 16 (Wednesday) at Mumbai's Wankhede Stadium.
England are in Group 1 with Sri Lanka, South Africa, West Indies and winner of Group B (from qualifying stage).