The Yorkshireman will represent Sydney Thunder alongside England Test vice-captain Jos Buttler in the competition that starts on December 19.
It will be Root’s first outing in an overseas franchise tournament after he went unsold in the Indian Premier League auction earlier this year.
England have sometimes rested him for T20 games because of his value to them in Test and one-day international cricket, but a break in the schedule ahead of next month’s tour to the West Indies has given the 27-year-old a chance he feels will benefit his overall game.
“It’s a great chance to evolve as a player,” said Root.
“You look at some of the guys who go to the likes of the Big Bash and from those experiences you see them grow.
“They come back into the international set-up and you can see the way they look at the game is slightly different. It adds to their thinking and gives them some form of an advantage in many different ways.
“To get the chance to do that, I’m really happy with it.”
Root and Buttler have been cleared to play in the first part of the competition ahead of England’s trip to the Caribbean.
Although Root is ranked fourth in the world in Test and one-day international cricket, he has played only 28 T20 internationals and does not want to be left behind in the game’s shortest format.
“I’m very excited to be involved with Sydney Thunder,” he added. “They’re a fantastic franchise and I’ll give everything I can for them.”