Mother Teresa will be made a saint on September 4.
Pope Francis set the canonisation date, paving the way for the nun who cared for the poorest of the poor to become the centrepiece of his year-long focus on the Catholic Church's merciful side.
The announcement was expected after Francis in December approved a second miracle attributed to Mother Teresa's intercession - the final hurdle to make her a saint.
The miracle involved the healing of a Brazilian man with several brain tumours in 2008, the Vatican said.
September 4 is the eve of the 19th anniversary of Mother Teresa's death.