The explosive fast bowler with the sling-arm action is expected to play a key role in Sri Lanka's fortunes in the 12-nation event starting on September 18.
Malinga will be the "face" of the World Twenty20 advertising campaign in the host nation and will promote the event globally, the ICC said in a statement.
"His distinct, stylish and colourful personality is synonymous with the intensity of Twenty20 cricket," the governing body added.
Malinga, 28, who gave up Test cricket last year to prolong his limited-overs career, said he was "honoured" to play a part in the first World Twenty20 to be hosted by an Asian nation.
"I sincerely thank the ICC for giving Sri Lanka the opportunity to host an event of this magnitude and I invite all cricket fans to show their support and unite in the spirit of the game," he said.
Malinga is the only bowler to have taken four wickets off successive deliveries in international cricket, achieving the feat against South Africa in the 2007 50-over World Cup in the Caribbean.
He is also the only bowler to have claimed three one-day international hat-tricks.
Malinga has taken 101 wickets in 30 Tests, 186 wickets in 118 one-dayers and 40 wickets in 32 Twenty20 internationals.
England will defend the title at the fourth edition of the World Twenty20, having won the 2010 event in the Caribbean. India (2007) and Pakistan (2009) won the first two editions.