Grant is from the Tai Tokerau region with links to Ngāpuhi, Ngātiwai and Te Rarawa Iwi. He was most recently the Chief Executive Officer of the Public Health Association of New Zealand. Prior to that, Grant spent four years working in regional economic development, firstly with the Ministry for Primary Industries (MPI), and then with the Provincial Development Unit, (MBIE) administering the Provincial Growth Fund in Northland.

He is a self-employed consultant specialising in Māori development matters and has extensive experience in the health, labour market and regional economic development sectors. He has been the CEO of the Raukawa Settlement Trust, CEO of the Ngati Kahu Social and Health Services Trust, the CEO of Hauora.com (a national Māori workforce development organisation), and a General Manager of Māori, Public Health and Mental Health at the Taranaki District Health Board.

Grant has also been the CEO of a Regional Māori Public Health organisation (Te Hau Ora o te Tai Tokerau), a National Māori Employment Commissioner, Northland Regional Manager of government work programmes, an auditor of health programmes, a Probation Officer, a Social Worker and also a freelance journalist for a Paris-based weekly newspaper. He has experience in policy development and implementation, funding, advocacy, facilitation and evaluation.  He has been a Government appointed member to the Youth Suicide Advisory Panel, Māori Mental Health Advisory Committee and a member of the Māori Advisory Board to the Public Health Directorate with the Ministry of Health.

In 2017, Grant, in conjunction with Dame Margaret Sparrow, was the recipient of the PHA Public Health Champions Award. In the new health environment, Grant is supporting the Maori Health Authority (Te Aka Whai Ora)  to develop their planning around Maori public health.