A National Missing Persons Day will be held annually from December and has been welcomed by support groups.
Justice Minister Alan Shatter said it will be an opportunity each year to remember missing people and their loved ones.
He said an event will be held on Wednesday, December 4, at Farmleigh House in Dublin to mark the special day.
The theme of this inaugural event is 'Forget Me Not' which has its origins in a project by transition students of Davis College, Mallow, Co Cork who were named Young Social Innovators of the Year 2012.
Minister Shatter said: "Ireland's first national Missing Persons Day presents an opportunity for us to remember those who have gone missing and acknowledge the difficulties experienced by their families and friends.
"It is also important to recognise the invaluable contribution and commitment of An Garda Siochana, the state agencies and voluntary groups working diligently in our commun- ities to highlight the issues and impacts surrounding people who go missing."
Dermot Connaughton, of Missing Irish Support Services, said: "It will be the first ever national day for the missing and it's a fantastic thing for the families. Many people have been working behind the scenes for such a day and it will be warmly welcomed."
While thousands are reported missing each year, 99pc are found in a relatively short period. Many families, however, suffer for long periods without any trace or contact with missing loved ones. People missing for long periods include:
* Esra Uyrun (38) went missing from her home in the Ronanstown area of Dublin on February 23, 2011 at 7am. Esra said she was going to the shops nearby. Her car was found in the Bray Head car park.
* Deirdre Jacob, of Roseberry, Newbridge, Co Kildare is missing since 1998. Deirdre, who was 18 at the time, was last seen at 3.30pm on July 28, 1998 walking towards her home.
* Martin Doyle (20), missing from his home in Suncroft, Kildare since October 4, 2004.
* Sionan O'Keefe (14), missing from her home in Clondalkin, Dublin. Sionan was last seen in the Charlestown area of Finglas at approximately 6pm on March 9, 2013.
* Claire Boylan (36) from the Terenure area of Dublin 6. Claire was last seen in the city on March 2, 2003.
* Josephine (Jo Jo) Dullard, missing since 11.30pm on November 9, 1995. At that time Jo Jo phoned her friend from a phone box in Moone, Co Kildare. She told her friend that she was hitching a lift to her home in Callan, Co Kilkenny. A short time later a woman answering Jo Jo's description was seen leaning in the back door of a dark-coloured Toyota Carina-type car. She was 21 when she went missing.
* Fiona Pender from Tullamore, Co Offaly was last seen at her flat at Church Street, Tullamore on August 23, 1996. At that time she was seven months pregnant and had spent the previous day shopping for baby clothes with her mother in Tullamore. She was aged 25 at the time.