63 new jobs have been announced for Co Mayo by Allergan.
The pharmaceutical company is to invest €65m in its operations in Ireland.
This latest investment is focused on the creation of two new manufacturing suites and a laboratory.
The new jobs in Westport will bring the pharmaceutical company's total employment in Ireland to more than 2,000 people across the country.
Allergan also has a manufacturing campus in Clonshaugh in north Dublin.
The Westport investment is set to focus on four areas.
Two new manufacturing suites in its biologics facility are to provide the capability to introduce new product formats for the company
There will also be the completion of a microbiology and a cell-based laboratory.
The Taoiseach, Leo Varadkar, welcomed the announcement, saying: "This is great news for Westport and for Mayo and reinforces the region’s deserved reputation as a location for investment and innovation.
"It is further evidence of the confidence international companies like Allergan continue to have in Ireland."
Paul Coffey, Vice President & Plant General Manager at Allergan Westport, said: "This €65m investment further cements Ireland’s strategic role in Allergan’s global network.
"Continued investment of this scale builds on the €50m investment programme in 2018 and €42m in 2017 which allows us to apply world-class technology to Allergan’s leading innovation and product development strategy.
"We are expanding capacity to meet global demand and we are advancing our R&D capabilities to meet the needs of the future for our business.
"We are proud that 40 years on we are still growing and offering valuable employment opportunities in key regions of Ireland and we thank the communities around us for their continued support.”