Two separate companies have announced 300 jobs in Dublin and Galway.
Global financial services company Fidelity Investments is creating 200 jobs in the technology and operations area.
The jobs will be based at the company's offices in Dublin and Galway.
The initiative is being supported by the Department of Jobs, Enterprise and Innovation through IDA Ireland.
The company set up in Ireland in 1996 and currently employs almost 500 people here.
Meanwhile, Dublin-based mobile gaming firm Swrve has secured a $6m investment, which it says will lead to 100 jobs.
The funding, from Atlantic Bridge Partners and Intel, will be used to expand Swrve's research and development operations in Dublin.