“The World Cup is the pinnacle of our sport and requires 100 per cent commitment and that’s something I’m unfortunately unable to give at the moment.
“I’ve loved being with this team under Dave (Rennie) and wish them all the best for their season and in the World Cup later this year.”
Head coach Rennie said the Wallabies worked to retain Wisemantel’s services, but were ultimately unable to persuade him to remain on.
“He’s hugely respected around the world, has a mountain of experience at International level and an incredible rapport with our players.
“While we did all we could to try and keep Scott, we respect his decision and wish him, Gabs and the girls all the best.
“He’s been a massive part of this group for the past three years and we’ll miss him.”
Wisemantel is the second coach to leave the side in the last six months, after defence coach Matt Taylor stepped away in August.
The Wallabies have begun the process in their search for a replacement, with a training squad set to enter a four-day camp on the Gold Coast next week.