Dawn Meats has been awarded a five-year, €300m contract by McDonalds to process up to 18 thousand tonnes of Irish beef a year.
The deal will see the investment of €14.5m in a new beef-processing facility in Caroll's cross Co Waterford, with the creation of 65 jobs.
One hundred jobs have also been created during the construction phase of the project - which started in December.
Previously, the Irish beef used by the fast food chain here had to be processed abroad.
Minister for Agriculture Simon Coveney described the deal as an enormous boost for the Irish beef sector.