The 58-year-old woman was arrested after police came across a “confronting scene” in an apartment north of Cairns on Tuesday night.
Police responded to reports of a serious assault at a Palm Cove address before 11pm when they discovered the elderly man in the living room.
The front door was locked when police arrived but after a forced entry the officers found the man alive but he was suffering “significant injuries”.
Detective Acting Inspector Jason Chetham said the man had multiple stab wounds about the torso, neck and back of the shoulder.
“Both front and back, so there was a few there. It was quite a confronting scene for our staff,” he said.
The man was taken to Cairns Base Hospital in a critical condition, where he later died from his injuries.
The 58-year-old woman was taken into custody at the scene and was later charged with murder.
“We don’t believe there is anyone else involved in this particular matter,” Det Chetham said.
Police said the woman did not live at the Palm Cove apartment.
“The exact nature of their relationship and why she was there is a focus of our investigation,” Det Chetham said.
A knife has been recovered.
“We have a weapon which we believe was involved in this offence,” Det Chetham said.
The woman is due to appear in Cairns Magistrates Court on Thursday.