Horse racing magnate JP McManus is just ahead of the Collison brothers to claim the title for Limerick.
*There are no entries from counties Fermanagh or Laois on the 2018 Rich List
Brian McCarthy owns Killorglin-headquartered Fexco which has seen its value rocket in recent years.
Denis O'Brien is originally from Cork. He owns Digicel, a major telecoms player in the Caribbean and Asia Pacific.
The Queally brothers Peter and John are major shareholders in the Dawn Meats group, one of the largest agri businesses in Europe.
Entrepreneur Terry Clune brought AIB on board to his business Transfermate last year valuing the business at up to €300m.
Beef baron Bert Allen and his family enjoyed a big payday when they sold Slaney Foods to Larry Goodman's ABP Foods.
David Walsh and Niall Kelly are the majority shareholders in Carlow-based security camera and software firm Netwatch. An IPO could value the company at €250m.
Kildare-born Ned Guinness, also known as Lord Iveagh, is one of Britain's biggest private landowners.
Media-shy Ryanair co-founder Declan Ryan is bringing low-cost airlines to several new markets.
Low-profile Patsy Perin Dubash was born on Hatch St and is married to Pallonji Mistry, who, along with their children, holds an Irish passport. The family's wealth comes from its stake in conglomerate Tata.
Stephen Grant owns around 58pc of Grant Engineering, which makes oil and solid-fuel burners and is based in Birr.
Luke and Brian Comer of Glenamaddy started off as plasterers but have built a property empire with interests in several countries.
Patrick Purcell and his family own the majority stake in London-listed mining equipment firm Mincon.
Although born in Cork, bloodstock billionaire John Magnier's world-renowned Coolmore Stud is based in Fethard.
Ryanair boss Michael O'Leary lives near Mullingar and has a big horse-training operation. He had a turbulent year in 2017 but remains one of the country's wealthiest men.
Property investor Charlie Kenny and family are behind the Clancourt group. It has seen its value rise significantly since the crash.
Eileen Monahan has enjoyed dividends from the Doyle Collection hotel group and is a canny property investor.
Raised in Ballinamore, Co Leitrim, Ray and Des O'Rourke own a chunk of construction giant, Laing O'Rourke.
Former Elan executive Seamus Mulligan made his money out of the biotech sector and is actively investing in new ventures.
Brothers Mike, Pat and Billy own Glennon Brothers, a major timber producer in Ireland and Scotland.
Although born in Louth, Martin Naughton now resides in Meath's Stackallan House, a classical Irish country house from the early 18th century. He built up Glen Dimplex, which now makes most of the world's home heating appliances.
Pearse Lyons made his money through animal nutrition business Alltech. More recently he has invested in a new Dublin whiskey distillery.
Tom Eakin is the brains behind innovative medical device company TG Eakin.
Tony White emigrated to America and developed a lucrative direct marketing business. He has invested in some fine New York properties.
Jim and Jack Dobson sold the Irish assets of Tyrone-based Dunbia to Dawn Meats last May.
Former motor racing journalist Paddy McNally sold his Formula One business for hundreds of millions. He owns several stunning homes in the UK and Europe.
Roma Downey and her husband Mark Burnett are hugely successful TV producers and are now making religious drama for Netflix.
Harold Montgomery and his family own Ballyvesey, a huge trucking company which has branched out into property in the UK and Europe.
Freddie Linnett started off as a tea girl but is now a major shareholder in a leading UK property company.
Insulated panels company Kingspan, founded by Eugene Murtagh, is one of Ireland's most successful listed companies.
There are no entries from counties Fermanagh or Laois on the 2018 Rich List
Rich List 2018
As 2018 gets under way, the economy is humming and the country is making its way back to full employment. With no let-up in the flow of foreign direct investment and with a chronic shortage in housing supply to be addressed, there will be no shortage of potential entrants to Ireland's property market as it once again becomes the only show in town.