Layton announced on Wednesday she will walk away at the end of Collingwood's campaign in the Super Netball competition early next month.

A large group of staff, current and past players as well as former Australian coach Norma Plummer, who gave Layton her first international cap at the 2011 world cup in Singapore, turned out at Magpies headquarters to farewell the popular defender.

With 46 Test appearances including a stint as captain, Layton hasn't played for the Diamonds since 2017 and stepped away from the sport entirely for almost six months to deal with mental health problems.

She said during this time she started to reflect on her 14-year career achievements, which include world titles with the Diamonds in 2011 and 2015 as well as Commonwealth Games gold in 2014.

"I know that this announcement may come as a shock to the netball community and a lot of people out there but it isn't a shock to myself and my close friends and family," Layton said on Wednesday.

"When I took time off from the sport it made me reflect on my career and I have achieved everything that I could ever have hoped and dreamed of in the netball world."

Layton wanted to test if she still felt the same once she regained her health and returned to the sport.

"In coming back this year I know for sure my time in the sport is done so there may be a few sad people out there but please know I'm really excited."

She said she wouldn't have been able to play again without the support of Netball Australia and the Magpies, and encouraged other people who may be struggling to seek professional help.

"I'm very proud to have been able to get back on court because to be able to perform under pressure after having gone through something like that is extremely difficult," she said.

Now in a good mental state, Layton said he wasn't sure what the future held but was looking forward to travelling.

She becomes the fourth decorated Diamonds player to announce their retirement from international netball in the last 10 days, joining former captain Laura Geitz, midcourter Madi Robinson and shooter Susan Pettitt.

Layton didn't make herself available for the current squad although admitted her form may not have warranted selection.

She said felt relieved after telling national coach Lisa Alexander, which further underlined her decision was the right one.

"When I came into the Australian side there was a changing of the guard and now it's happening again which is really exciting for Australian netball," Layton said.

SHARNI LAYTON'S CAREER:

DOMESTIC:

Super Netball team: Collingwood Magpies (Previously - Melbourne Kestrels, AIS Canberra Darters, Melbourne Vixens, Adelaide Thunderbirds, NSW Swifts)

Games: 141* (as of round 11)

Premierships: 2010, 2013 (Thunderbirds)

Australian ANZ Championship Player of the Year (2016)

INTERNATIONAL:

Australian Diamond debut (Singapore, 2011)

46 Test caps

Netball World Cup Gold (2011 Singapore, 2015 Australia)

Commonwealth Games Gold (2014 Glasgow)

International Player of the Year (2016, 2017)

Australian Diamonds captain (2017)

Australian Associated Press