Four new funds worth a total of €4 billion have been launched as part of the Project Ireland 2040 investment.
The Republic's government announced that the funds, which are part of the €116 billion project, will be invested in rural development, urban regeneration, climate action and innovation.
The taoiseach said the money will be allocated competitively to the best projects and the call for applications will open in the coming weeks.
Half of the €4 billion will be put towards urban regeneration in Dublin, Cork, Limerick, Galway and Waterford, alongside 54 other urban centres.
Rural areas are set to be given €1 billion and towns with a population of less than 10,000.
The remaining €1 billion will be split evenly between the Climate Actions Fund and the Disruptive Technologies Fund.
Speaking at a press conference on Wednesday, Leo Varadkar said: "We expect our country's population to grow by more than a million over the next 20 years, with two-thirds of a million more people at work.
"That is a huge level of growth for a country of our size and we must plan for it now.
"Project Ireland 2040 seeks to ensure that 75 per cent of this growth will take place outside Dublin and, in particular, we have set the ambitious target that the cities of Limerick, Cork, Galway and Waterford will grow at twice the rate of Dublin.
"The four funds being launched today will drive that growth and ensure that all regions have an opportunity to benefit in the economic expansion that lies ahead."
