In 1999, as co-founder, he served as the inaugural chair of the G20 Finance Ministers and Central Bank Governors and continued in that position for 3 years.

After leaving public life, Mr. Martin advised the African Development Bank and has worked closely with the Advisory Council of the Coalition for Dialogue on Africa. He was also a founding co-chair of the Congo Basin Forest Fund and a Commissioner for the Global Ocean Commission.

In 2009, the Martin Family Initiative (MFI) was founded as a private foundation committed to improving education, health, and the overall well-being of Indigenous children and youth in Canada. Since its inception MFI has sought to walk the path with Indigenous schools and communities as they define their priorities and goals, bridging the gap between community needs and available resources and expertise. MFI accomplishes these goals based on the founding precept that every community and school should have the tools available to them to provide their children and youth with every opportunity possible. To this end, MFI gathers the most relevant expertise beginning with community-based knowledge to co-develop, support, and implement innovative programming and networks that centralize Indigenous ways of knowing. By working hand in hand with Indigenous people on the ground, MFI seeks to develop lasting programs that are created with and maintained by the communities themselves.

In 2012, he was appointed Companion to the Order of Canada.

He is married to Sheila Ann Cowan and they have three sons and five grandchildren.