WhiteHat Security provides web security services to businesses, including e-commerce, financial services and healthcare companies.
The new jobs will be created following the establishment of a threat research centre, customer support and software engineering operation.
Invest NI has offered the company an employment grant of £400,000.
WhiteHat Security will also get £80,000 of support under the agency's Skills Growth Programme to develop its Belfast team, while the Department for Employment and Learning has offered support of up to £240,000, towards pre-employment training costs.
The company will recruit 50 security engineers, 20 software engineers and 10 customer support staff over the next three years.
Enterprise Minister Arlene Foster said: "It is very welcome news that another leading ICT company has decided to locate in Northern Ireland.
"WhiteHat Security is a rapidly expanding company that is leading the field in the area of web security.
"The ICT sector is an important and growing cluster for Northern Ireland; and WhiteHat is a welcome addition to our important IT security sub sector."
Eighty jobs are to be created in Belfast by an American web security firm.