The charity has launched its annual Christmas campaign
A charity that supports older people say one-third of the people who use their services have nowhere to go on Christmas Day.
Alone is highlighting the isolation and loneliness of older people around this time of year.
At the launch of its annual campaign, broadcaster Anne Doyle urged members of the public to reach out to the older members of their community this Christmas and offer support to those living alone.
"I have been an admirer of the work of Alone for many years and I am delighted to help them launch their Christmas campaign this year.
"Loneliness and isolation can be real problems for older people and it's important that we are all aware of this", she said.
Sean Moynihan, CEO of Alone, added: "No one should feel alone at Christmas, however, in Alone we meet many older people who have no one to celebrate this special time of year with.
"Over time they have lost loved ones and become cut off from their local community. Some of the older people we work with might not see anyone from one week to the next."
"Over the winter period calls for support dramatically increase and loneliness is one of the main issues that older people face.
"I don't think that people are aware just how devastating loneliness can be for your general health. Not only can loneliness lead to depression, but it is also a predictor for dementia, cardiovascular disease and decreased immune system responsivity.
"Loneliness is twice as dangerous to the health of an older person as obesity, and is as damaging as smoking 15 cigarettes a day."
In general, the charity says one-third of people aged over-65 live alone on a day-to-day basis.
The number of over-65s living in Ireland is expected to increase to 1.4 million by 2046. In 2015, that figure stood at 606,000.
The charity also says that 50% of calls it received in 2014 were from older people looking for support around homelessness or housing.
It also saw a huge increase in the number of older people who were being evicted from their private rented accommodation due to increasing rents.
Last year, Alone received €166,482 in general donations - it says 100% of this went towards services.
There are a number of ways that the public can help an older person this Christmas.
This Christmas, Alone will see 500 volunteers befriend older people and deliver 500 hampers to them.
The charity says it will also deliver 150 Christmas dinners to older people.
As well as that, an additional 200 older people will get other supports - including by phone.
Alone can be contacted on (01)-679-1032. You can make a donation and help here.