The Silver Ferns star had initially been linked to teams in Queensland and Sydney, but will bring much-needed star power to the struggling Adelaide side.

Folau, 31, said she was excited to join the Thunderbirds, having previously played for the Northern Mystics in the New Zealand league.

"It will be a new team, new dynamics, new playing styles, so this is a real game-changer for me to challenge myself and play the best netball that I can," she said.

"The club has a great history - it's an awesome opportunity to be part of that success again."

Folau played about half of the Mystics' 2018 games after moving to Sydney last year to be with her husband, Australian rugby superstar Israel Folau.

Netball New Zealand has granted her a 12-month exemption, meaning she is still eligible to play for the Silver Ferns in 2019 despite no longer being contracted to a New Zealand Premiership team.

Coach Tania Obst said Folau was a "significant signing", after the Thunderbirds failed to win a single game in the recently-completed campaign.

"I'm most excited about the wealth of experience, the world-class quality that Maria will bring to our team and the contribution that she'll be able to make to our team both on and off the court," Obst said.

"Maria is an incredible player, a superior athlete and sets the Adelaide Thunderbirds up for a strong, successful and competitive season."

Folau joins several other international Thunderbirds signings, including English players Layla Guscoth and Beth Cobden and Jamaican goalkeeper Shamera Sterling.

Australian Associated Press