John Peters Humphrey was born in Hampton, New Brunswick on April 30, 1905. He studied at Rothesay Collegiate School (now Rothesay Netherwood School), Mount Allison University in Sackville, New Brunswick, and McGill University in Montreal. Humphrey practiced law from 1929 to 1936, when he joined McGill's Faculty of Law as a professor.
In 1946, Professor Humphrey was appointed as the first Director of the Human Rights Division in the United Nations Secretariat. He was a principal drafter of the Universal Declaration of Human Rights. At that time Eleanor Roosevelt chaired the executive group of the Commission. The General Assembly unanimously adopted the Declaration, dubbed by Mrs. Roosevelt as "the international Magna Carta of all mankind" on December 10, 1948. In 1963, he proposed the idea of a United Nations High Commissioner for Human Rights that while initially received quite positively took more than thirty years to become a reality, under Secretary-General Dr. Boutros Boutros-Ghali. He was made an Officer of the Order of Canada in 1974, "in recognition of his contributions to legal scholarship and his world-wide reputation in the field of human rights". Professor Humphrey remained with the UN until 1966 when he retired to resume his teaching career at McGill University. On the 40th anniversary of the Declaration (1988), the UN Human Rights Award was bestowed on Professor Humphrey.
Professor Humphrey remained a human rights advocate in Canada and internationally until his death on March 14, 1995 at the age of 90. He was a director of the International League for Human Rights; served as a member of the Royal Commission on the Status of Women; and part of the team that launched Amnesty International Canada. Professor Humphrey with colleagues from McGill University was instrumental in creating the Canadian Human Rights Foundation.
Professor Humphrey left a lasting legacy regarding human rights worldwide. The McGill University Faculty of Law has held the John P. Humphrey Lectureship in Human Rights since 1988. This is an annual lecture on the role of international law and organizations in the worldwide protection of human rights. The John Peters Humphrey Model United Nations is an annual May event in Fredericton, New Brunswick. The John Humphrey Freedom Award, presented by the Canadian human rights group Rights & Democracy, is awarded annually to organizations and individuals worldwide for exceptional achievement in the promotion of human rights and democratic development. In June 2008, a memorial to Dr. Humphrey located just a few h hundred yards from his childhood home, was unveiled in his hometown of Hampton, New Brunswick.