Five companies are to create a total of 167 jobs in Dublin and Cork.
The positions will be spread across a number of sectors, including ICT, financial services, medical technology and digital media.
Jobs Minister Richard Bruton said it was great news that the organisations, from both the US and Europe, had chosen to invest in Ireland.
"Part of the Government's plan for jobs and growth is ensuring that we attract more fast-growing start-ups and emerging companies to locate in Ireland, so that they establish deep roots here from early in their growth and make a substantial impact on our economy," Mr Bruton said.
"There is also, of course, the possibility that one of these companies will turn into a world-leading company of the future."
ICT firm 10gen will create 60 jobs at a new customer and technical support centre at its European headquarters in Dublin.
Software training firm Loop1 Systems Inc and US-based Whitehouse Analytical Labs will create 17 and 35 positions respectively in Cork.
Medical device firm IMSTec Gmbh will also offer 35 positions in Cork while PE Lynch, which produces trading software for banks and brokers, will launch its European headquarters in Dublin with 20 new jobs. Online store Etsy also announced the establishment of its European headquarters in Dublin.
Barry O'Leary, chief executive of IDA Ireland, which helps secure foreign investment to the country, welcomed the new jobs.
"These six companies announcing investments and job creation in Ireland today have come to Ireland in order to take advantage of our wealth of talent, track record as a location for FDI (foreign direct investment), technology capabilities and attractive rate of corporate tax," he said.