The tragedy unfolded after a rescue operation at Glenarm involving the Coastguard and RNLI shortly before 1pm on Thursday.
A Coastguard helicopter lifted the woman from the water before she was transferred to hospital.
A PSNI spokesperson said the PSNI ‘responded to a report of a woman in the water in the Coast Road area of Glenarm shortly before 1.45pm’ on Thursday October 19.
"Medical assistance was provided at the scene,” he said.
"Sadly, a short time later the woman was pronounced dead as she was being transported to hospital.
"The death is not being treated as suspicious at this time.
" Anyone who witnessed what happened is asked to contact police on 101, quoting reference number 944 19/10/23."
A post on HM Coastguard Larne said: “Around 1300 hrs on Thursday HM Coastguard Larne, Portmuck Coastguard, Larne RNLI and Redbay Lifeboat was tasked to Glenarm, both Coastguard technicians and RNLI lifeboat crew worked tirelessly until paramedics of Coastguard rescue 199 arrived to take over along with northern ireland ambulance service.
"Our thoughts will continually be with the family and friends affected”.
And later at 5.20pm the page adds that “both Larne and Portmuck Coastguard rescue teams where tasked again to reports of a person falling from a cliff, in a coordinated effort Coastguard cliff technicians, fire service SRT and ambulance Hart technician were deployed down the cliff to the casualty.
"Coastguard rescue 199 was on scene but due to the poor weather conditions they where unable to assist.
"Casualty was recovered by stretcher and into the care of ambulance service for onward journey to hospital”.