The pensioner was taken to hospital after being found with serious injuries at her home in Edinburgh's Morningside area earlier this month.
Police Scotland said a 23-year-old man was arrested following the alleged attack on Friday July 11.
He is expected to appear at Edinburgh Sheriff Court today.
A force spokesman said: "Police Scotland will continue to work with our partners to offer reassurance to the community and high-visibility patrols will still be present in the area.
"Police would like to thank the public for their patience while we carried out inquiries in relation to this incident."