Iacobucci, who was a Supreme Court judge from 1991 until his retirement in 2004, will report directly to Michael Gravelle, Ontario's minister of northern development and mines.
The province says Iacobucci will also be supported by the Ring of Fire Secretariat in his negotiations with nine First Nations in the area over resources development.
"The Ring of Fire is a wonderful opportunity for Ontario to create jobs and grow its regional economies, but it is vital that we work with First Nations communities to make sure this development brings long-term, sustainable benefits," Ontario Premier Kathleen Wynne said in a statement Tuesday.
"I am very pleased that the Honourable Frank Iacobucci has agreed to lead negotiations for Ontario. His expertise as a negotiator and experience with First Nations communities in northern Ontario is a tremendous asset to this important process."
Sitting across the negotiating table from Iacobucci will be former Liberal MP Bob Rae, representing the Matawa Tribal Council. Rae resigned his seat in the House of Commons last month to focus his attention on the negotiations.
The Ring of Fire, located 540 kilometres northeast of Thunder Bay, Ont., is a treasure trove of minerals and contains the largest deposit of chromite — a key ingredient in stainless steel — ever discovered in North America.
Both the federal and provincial governments have high hopes for billions of dollars of investment in the Ring of Fire — development they hope will bring prosperity to struggling First Nations and royalties to their own coffers.
Federal and provincial ministers have compared the region to the Alberta oilsands in terms of its potential to produce wealth and development.
This is not the first time Iacobucci has worked with the province on aboriginal issues.
The Ontario government previously asked him to look into the lack of First Nations representation on juries. In February, Iacobucci released a report that found aboriginals face "systemic discrimination" when it comes to criminal justice or child services and the courts — especially in the north.
Last month, the province set up a panel to oversee the implementation of Iacobucci's recommendations.
Iacobucci has stayed in the public eye since his retirement from the Supreme Court.
Several years ago, the federal government called on him to oversee an inquiry into torture allegations levelled by three Arab-Canadians. The inquiry concluded in 2008 that Canadian officials were probably at least partly to blame for the torture of the three men.