The new Rivers Headquarters has been opened by the Infrastructure minister in Cookstown.
The new £2 million building is on the Loughry Campus and accommodates up to 85 staff.
The facility will also provide hot desks for other Civil Servants to use when working in the area.
Chris Hazzard said the relocation is about a fairer distribution of good quality public sector jobs.
He said: “I welcome the relocation of the DfI Rivers Headquarters staff and functions to Cookstown as it demonstrates delivery on the commitment to bring good quality Civil Service jobs west of the Bann.
“The opening of this new £2million state of the art office provides a modern working environment for staff. The facility will also provide hot desks for other Civil Servants to use when working in this area.
“The relocation is about helping to achieve a fairer distribution of good quality public sector jobs by making sure we create employment in rural areas as this will stimulate the local economy.”