In a separate post on Instagram, he said Maria was a nurse for 36 years.
"She was the sweetest of all sweethearts. Always giving love."
Just two days ago, the Sydney-born children's entertainer posted a recent photo with Maria on Instagram.
In the caption he spoke of "how lucky" he was to have a sister that "looked after me".
Condolences have started streaming in from fellow entertainers.
Country musician Troy Casser-Daley said: "Mate so sad Anto, love to all your family brother x".
The Chaser's Andrew Hansen said: "Very sorry to hear, Anthony".
It's been a rough couple of years for the man behind the blue skivvy.
Last year Field was rushed to hospital in Boston after a nasty accident during the group's US tour.
He needed 12 facial stitches after colliding with a revolving door.
The beloved entertainer also revealed he was experiencing "vision problems" after he was photographed wearing an eye patch at an Australia Day concert.
In 2007, the father of three went public about his battle with depression, describing the rigours of constant touring and how he was left feeling isolated despite his fame.
