This year's Day for the Poor collection is scheduled for Sunday 9 November with all funds going to St Catharine's Mercy Centre in Lauriston, Edinburgh.
The centre is run by the Sisters of Mercy and offers meals, toilet facilities, advice on welfare and a place of refuge and calm.
Sr Aelred Timmins RSM said: "In Edinburgh there are so many homeless people on the streets.
"They come here every day for food, sometimes for sleeping bags, most of all they're looking for friendship and a listening ear.
"We are a Mercy Centre and we welcome everybody in. Our whole charism is 'response to need'.
"Please keep us in your prayers, and we really are very grateful to anybody who is able to support the works of mercy in this house."
Sr Aelred and the Sisters of Mercy established the Homeless Project at St Catharine's Mercy Centre in Lauriston Gardens in 1993 and it can help up to 200 people each day.
Parishes have been asked to hold a special collection at Mass on Weekend of 8/9 November (or nearest suitable date). To donate online please tap here.