The 23-year-old replaces John Hastings in the side after the Australian pacer was forced to retire following a premature lung condition. Curran is likely to play a vital role for the Sixers in this year's tournament.
"I'm absolutely delighted to be joining the Sydney Sixers for the 2018-19 Big Bash," Curran said. "Friends and colleagues have told me what a great team environment it is and how passionate the fans are and I'm hugely excited to experience this all for myself.
"I can't wait to get to Sydney and hopefully help the team have a great season."
Curran has so far played two Tests, 11 One-Day Internationals and seven Twenty20 Internationals for England. He returned career-best figures of 5/35 in just his third ODI against Australia and more recently was part of the England ODI and T20I side that toured Sri Lanka in October.
The Englishman was also part of the Kolkata Knight Riders squad for the 2018 IPL season but has been released by the side for the upcoming edition. He joins fellow England teammate Joe Denly in the Sixers unit.
Sydney Sixers squad: Moises Henriques (c), Sean Abbott, Joe Denly, Mickey Edwards, Ben Dwarshuis, Daniel Hughes, Nathan Lyon, Peter Nevill, Stephen O'Keefe, Josh Philippe, Lloyd Pope, Jordan Silk, Henry Thornton, Tom Curran, Justin Avendano, Dan Fallins
First Published: December 4, 2018, 2:11 PM IST