The jobs are to be created over three years in a £29.9 millio investment.
Invest Northern Ireland has offered £4 million of public money for the new jobs, which will bring the total employment at the Newtownabbey site to 945.
Capita Managed IT Solutions was formed in 2013 when Capita plc acquired Northgate Managed Services Ltd.
The Department for Employment and Learning (DEL) is to stump up £1.2 million of training support for the investment.
DEL Minister Stephen Farry said: “This investment by Capita emphasises the importance of the availability of a highly skilled labour force to support business growth and expansion particularly in key growth sectors such as IT.
“My department’s Assured Skills programme will provide a package of support including tailored training and development programmes to ensure Capita has the skilled workforce they require.”
Capita provides IT services for public, private and third sector organisations across the UK.
Its managing director Ed Brown said: “The business is seeking to grow its customer base, expand its service range and significantly increase its service delivery capabilities in Northern Ireland.
“This investment is part of our strategy for achieving these objectives.
“Given the opportunities in the marketplace and the quality of services and people already in place, we believe that we can reach our growth targets.”