Peter Conway, former Council of Trade Unions secretary, died in Wellington today.
A family statement said he battled a depressive illness for more than a year and carried it with the same dignity and kindness that he lived his life.
"Peter committed his whole working life to improving the lives of working people, both in unions and, more recently, as the economist and secretary of the Council of Trade Unions.
"He was previously Chair of Oxfam New Zealand and was on the Board of NZ Trade and Enterprise," the statement said.
Labour leader Andrew Little said Mr Conway was a stalwart of the labour movement whose dedication to the rights and wellbeing of all New Zealand workers was enduring and determined.
"He was a good man and he will be held in the hearts of the labour movement," Mr Little said.
Green Party co-leader Metiria Turei said Mr Conway was a brilliant economist and a kind and gentle person.
"Peter had experience at the coalface and in the board room and was deeply respected on both sides of the industrial fence, by both workers and employees," she said.
"Peter had a highly compassionate view about how an economy can work well for everyone and he will be profoundly missed by many who shared in his brilliance.
"Our deepest sympathies are with Peter's family and friends."
Mr Conway is survived by his partner Liz and three children.