The 31-year-old last played a T20 international in October 2011, but in July was named by CSA in a 30-man provisional squad for the global event.
There was, however, a place in the squad for all-rounder Jacques Kallis, who has played just one T20 international for his country since May 2010.
"We are confident that our squad will be very competitive and make South Africa proud. We have had basically the same squad together for the past year and many of them also produced stand-out performances at the Indian Premier League," CSA selection convener Andrew Hudson said.
The World T20 starts in Sri Lanka on September 18 with South Africa drawn in the same group as the hosts and Zimbabwe.
In an effort to gain some valuable match practice ahead of the global showpiece, the same 15-man squad will play a three-match T20 series in England next month.
"The Proteas will also have excellent preparation for the World Twenty20 by finishing the England tour with three matches. They may be playing on a different surface to that they will find in Sri Lanka but they will be able to hone their T20 specific skills," Hudson added.
Squad: AB de Villiers (captain), Hashim Amla, Farhaan Behardien, Johan Botha, JP Duminy, Francois du Plessis, Jacques Kallis, Richard Levi, Albie Morkel, Morne Morkel, Justin Ontong, Wayne Parnell, Robin Peterson, Dale Steyn, Lonwabo Tsotsobe