Nua Healthcare, Veolia, Boxever and Netigate will separately create the jobs over the next five years
1245 new jobs have been announced across four companies today.
Intellectual Disability Care Service providers, Nua Healthcare has announced 800 new jobs over the next three years.
The company is developing new residential and day care facilities.
300 of the positions are to be delivered in 2016.
Environmental services company Veolia is generating 300 jobs here.
They are starting to recruit for their Co Mayo biomass plant, and will build another two by 2020.
Veolia plans to fill all 300 positions within five years.
Online and cloud-based roles
Elsewhere, online marketing company for the travel industry Boxever, is to create 100 new jobs in Dublin.
The firm is recruiting data scientists and software engineers.
Speaking on Newstalk Breakfast their Chief Executive Dave O Flanagan said it was a good start to the new year:
"We intend to hire another 100 people over the next 18 months in Dublin. That has grown from last year when we were 30 people, this year we doubled and thanks to very strong demand for our product we intend to add primarily data scientists, software engineers, high value technical roles.
Meanwhile, Netigate, a leading European provider of cloud-based services for online surveys has announced 45 jobs.
Netigate is establishing its International Headquarters in Cork, and is recruiting for technical support and account management roles.