Combined council chairman Vaughan Renner welcomed the appointment.
"We are delighted to have been able to attract someone of his calibre. His knowledge and experience across business, membership, and advocacy organisations will be of huge benefit to our members and the business community.
"We look forward to him returning from Melbourne in March, once completing MIQ requirements."
Arcus, who became a CEO for the first time at 38, said he saw the job to be about "giving businesses a voice and a home that helps them thrive".
"I'm looking forward to my Wellington return as I grew up there, and it's definitely home. We have some wonderful, innovative businesses in the region that are, in my view, the undiscovered gems of our business community. I look forward to working alongside passionate people who want to see the whole region succeed."
Previously, Arcus served as chairman of the Wellington Cancer Society and on the Scots College board of governors.
Prior to his current role, he held leadership roles in advocacy and membership organisations, including the Victoria Farmers Federation and Master Builders Association of Victoria, and before this as chief executive at the New Zealand Institute of Directors.