The star, who passed away at the Cairns Base Hospital, close by her Queensland home, rose to fame in the early 1960s opposite stars such as Charlton Heston.
In 1963 she played the role Molly in the movie Tom Jones and was nominated for a supporting actress Oscar.
Michael Gow, a close friend of Diane, paid tribute by saying she was "a performer to the end"
"She kept us all hugely entertained until the day before yesterday, when she just couldn't manage anymore and we took her to hospital".
The cause of death hasn't been made public.
Cilento was awarded a Queensland Greats Award in 2001 in recognition of her status as a National Treasure.
Cilento also had her biography published in 2006 which was called My Nine Lives.
"While she was originally known as a glamorous international film star, her work in later years in the far north showed her commitment to the arts," said Queensland state Premier Anna Bligh, in a statement.
"I know that Ms Cilento will be sorely missed by many in the industry.
