The nun who cared for the "poorest of the poor" will officially become a saint later this year.
Pope Francis set the canonisation date, paving the way for the nun 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 actual date, September 5, falls on the eve of the 19th anniversary of her death.
The ceremony will draw tens of thousands to honour the tiny, stooped nun who was fast-tracked for sainthood just a year after she died in 1997.
St John Paul II, who was Mother Teresa's greatest champion, beatified her before a crowd of 300,000 in St Peter's Square in 2003.
Born Agnes Gonxha Bojaxhiu on August 26 1910, in Skopje, Macedonia, Mother Teresa joined the Loreto order of nuns in 1928.
In 1946, while travelling by train from Calcutta to Darjeeling, she was inspired to found the Missionaries of Charity order.
The order was established four years later and has since opened more than 130 houses worldwide to provide comfort and care for the needy, dying, sick and "poorest of the poor".
Mother Teresa won the Nobel Peace Prize in 1979 for her work with Calcutta's destitute and ill - work which continued even after she herself became sick. She died on September 5, 1997 aged 87.
At the time, her Missionaries of Charity order had nearly 4,000 nuns and ran roughly 600 orphanages, soup kitchens, homeless shelters and clinics.
Rev Bernardo Cervellera, editor of the Vatican-affiliated missionary news agency AsiaNews, said: "She built an empire of charity.
"She didn't have a plan to conquer the world. Her idea was to be obedient to God."