Born in Salt Lake City, Utah, he completed high school there in 1928.While he did not go on a mission for the church at the customary age of 19, after attending the University of Utah he did go on a mission in 1933 and one could say that he has been on that mission ever since. By the time he returned to the United States in 1935, he had been a personal assistant to apostle Joseph F. Merrill, who presided over all the church's European missions, and who obtained an interview for him with the Church's First Presidency, which led to his becoming a full-time Church employee. Hinckley's responsibilities under President Heber J. Grant included publicity and developing the Church's fledgling radio (and later television) broadcasts, and from 1937 he served on the Sunday School General Board.
After service in a stake presidency, he became a General Authority of the Church in the discontinued position of Assistant to the Quorum of the Twelve Apostles in 1958. In 1961 he himself became an Apostle and member of that Quorum, the youngest at that time.
In the early 1980s the ill health of both Church President Spencer W. Kimball and his octogenarian Counselors Nathan Eldon Tanner and Marion G. Romney led the Church leadership to resort to the occasional practice of adding an additional member of the First Presidency beyond the President and First and Second Counselors, and on July 23, 1981 Hinckley became an additional Counselor. On Tanner's death in 1982 Romney succeeded him as First Counselor and Hinckley succeeded Romney as Second Counselor.
By this time however Hinckley was largely shouldering the burdens of the First Presidency himself, and though nominally his title remained Second Counselor, he was informally referred to in the press as "acting president of the church". Kimball and Romney were rarely seen in public until Kimball's death in November 1985.
Longtime President of the Quorum of the Twelve Apostles Ezra Taft Benson became Church President, and named Hinckley First Counselor, Romney nominally succeeding Benson as President of the Twelve though he never exercised the comparatively light duties of this position. Thomas S. Monson became Second Counselor, and for a while Hinckley's burdens were shared among a functioning First Presidency.
In the early 1990s however, the nonagenarian Benson developed serious health problems that removed him from public view, and First Counselor Hinckley was again viewed as "acting president" until Benson died in 1994. Howard W. Hunter, who had succeeded Romney as President of the Twelve, became Church President and confirmed Hinckley and Monson as his Counselors, Hinckley additionally becoming President of the Twelve by seniority. And when Hunter died after a presidency of only nine months, seniority made Hinckley president of the Church itself at the age of 84 (his two predecessors had both acceded at age 86).
Vigorous for his age, Hinckley has led the Church since, now the fourth oldest president in Church history. He has held steadfastly to some policies while moderating others.