A new €130m mozzarella manufacturing plant will be built in Portlaoise.
Glanbia and the US company Leprino Foods announced the plans this morning.
Almost 80 full-time jobs will be created at the factory, as well as 250 jobs during construction.
Minister Charlie Flanagan described the announcement as a "great day for Portlaoise and the Midlands."
"This is a great day for Glanbia Cheese, Portlaoise and the Midlands region. The economic growth of our regions through the creation of sustainable jobs is a priority for Government, and I am delighted to see this level of investment and such a significant number of jobs being created here today – most certainly a welcome boost to the economy of Portlaoise.
"Glanbia’s continuous investment here shows their commitment and confidence in Ireland, our dairy excellence and our talented workforce. I congratulate Glanbia, Leprino Foods and Enterprise Ireland and look forward to their continued success here in Portlaoise."
Siobhán Talbot, Group Managing Director of Glanbia added: "We are pleased to announce plans to build this new facility for Glanbia Cheese.
"Our partnership with Leprino Foods has been very successful for both partners to date and we are very positive about the potential of this new venture.
"We have worked closely with Enterprise Ireland on this project and are very appreciative of their support and commitment. We now look forward to moving the project on to its next phase."