The 47-year-old will coach Australia in all three formats of the game and will commence in the role on 22 May, for a four-year term taking in two Ashes Series, a World Cup and World T20 tournament.
The WACA has begun the process of appointing Langer’s replacement and will provide further information as it becomes available.
WACA CEO Ms Christina Matthews said:
“I’m sure I speak for the whole WA cricket family when I say that we are as thrilled as we are proud following this announcement.
“Justin has been an invaluable contributor to WA cricket since his appointment in 2012 and his leadership and guidance off the field has been as important as the results he and his support team have produced on it.
“When Justin was announced as coach of WA, he spoke of reviving the strong bond that existed within the WA cricket family; of making every contributor at every level of the game in this state, take pride in the role they were playing to grow and develop the sport. I firmly believe that Justin – and many others, also – has achieved that goal.
“We have a lot of good people involved in WA cricket who have helped the community stand taller and we’re proud of what Justin has helped us achieve over the past six years.
“Justin is unashamedly passionate about his home state, but if there’s anything that comes close to the level of enjoyment he takes in seeing WA succeed, it’s seeing Australia succeed and I have no doubt he will devote all his energy and talent to helping achieve that.
“We again congratulate Justin and wish him all the best – the entire WA cricket family that he helped make stronger than ever is right behind him.”