Rees Tapsell (Ngāti Whakaue - Te Arawa Waka) was born and raised in Rotorua with his three siblings. He attended Western Heights High School before completing an undergraduate medical degree at the University of Otago. After several years working in primary care, Rees and his wife travelled to England, where he began psychiatric training, ultimately returning home to Wellington, where he completed his fellowship with the Royal Australian and New Zealand College of Psychiatrists. Rees sub-specialised in forensic psychiatry, working at the Mason clinic in Auckland as a consultant psychiatrist for ten years where he worked on, and wrote about, models of forensic mental health service provision for Māori. He has worked in governance, operational, management and clinical leadership roles both in district health boards and Māori non-governmental organisations. Over the past six years, Rees has been the Director of Clinical Services for the Mental Health and Addictions Services of the Waikato District Health Board.