Two US companies have said they hope to create around 300 jobs in Dublin and Cork.
Software security company FireEye is to establish its new technical support centre in Cork with the creation of 150 jobs.
Recruitment is expected to begin immediately.
FireEye provides software protection against web and email next-generation security threats.
The investment is supported by the Department of Jobs, Enterprise and Innovation through IDA Ireland.
Senior vice president of customer support at FireEye Tony Kolish said: "Putting FireEye’s EMEA technical support centre in Ireland was an obvious choice due to the country’s successful track record in technology, an existing cluster of high-tech companies, and the availability of competent, multilingual talent."
Elsewhere, marketing software company Hub Spot has announced the creation of around 150 jobs in Dublin.
Hub Spot is expected to create jobs in sales, support, marketing, engineering and development roles. It employs 22 staff in Dublin.