The firm revealed on Thursday its expansion of its Belfast operation would create 300 more jobs than the 700 first projected to be in place by 2019.
Chris Lyttle MLA said: “This is fantastic news for Belfast, with Deloitte now planning 1,000 new jobs by 2020 – making Belfast its largest hub outside of London.
“This announcement is a strong vote of confidence in the local workforce, which has the skills and expertise to attract high value jobs.
“A fantastic boost for our regional economy, we should be doing all that is possible to showcase Northern Ireland as a valuable location for other major companies.”