The woman, who is from England but who owns the only house on Lahan Island, fell just after 8am this morning.
The woman, who is in her 80s, suffered a number of fractures to her body but managed to contact the emergency services using her mobile phone.
The Arranmore Lifeboat rushed to the scene and reached the woman at around 8.40am.
She was stretchered from the island and transferred by lifeboat to the mainland at Cloughglass.
Once on the mainland she was then taken by the Rescue 118 helicopter based in Sligo and rushed to Letterkenny General Hospital.
Her condition has been described a stable.
The woman spends several weeks of the year on the island which is only about 300 yards in length and contains just one house.
Nora Flanagan of the Arranmore Lifeboat, said the woman was lucky she had her mobile phone with her.
“Once we got the call we rushed to the scene and the woman was taken by stretcher to the mainland where she was assessed and flown to Letterkenny.
‘The woman is the only inhabitant on the island and she was lucky that she had her phone and was able to contact the emergency services,” she said.
Ms Flanagan revealed that the Arranmore Lifeboat has responded to 21 various calls in recent weeks.