Prof Fergusson worked in the Department of Psychological Medicine and led the 35-year study of a birth cohort of 1265 children born in the Christchurch region in mid-1977.
The study has informed government policy decisions on topics such as child sexual abuse, youth drug use and abortion.
University vice chancellor Harlene Hayne, who wrote several book chapters with Prof Fergusson, said in a statement today he was "considered an international leader among life course researchers, using sophisticated methods to extract maximum impact from social survey data".
To people who worked with him, Prof Fergusson was "both our harshest critic and our fiercest ally", Prof Hayne said.
"To described him as a national treasure is perhaps the only fitting way to capture the enormity and importance of his contributions to his adopted country over 40-plus years."
"His work ethic was second to none," Prof Hayne said.
"This work ethic was driven by the desire to generate knowledge that would make life better for the most disadvantaged among us. His strong personality and sheer force of will has touched many New Zealanders in different ways."
After retiring from the university in 2015, Prof Fergusson worked as a consultant for the Ministry of Social Development.