She was among five to be granted sainthood by Pope Francis during Canonization Mass at the Vatican, reports Efe news.
John Henry Newman, an English theologian who converted to Catholicism at the age of 44, Marguerite Bays, who was from Switzerland, Mother Marian Thresia Mankidiyan, from India and Giuseppina Vannini, from Italy, were also made saints.
As is custom, Francis proclaimed the sainthoods in Latin and asked that their names be written into the Church's book of saints.
The ceremony coincides with the Amazon Synod.
Born in Salvador de Bahia on May 26, 1914, the Brazilian nun was officially baptized as "Saint Dulce of the Poor" in the presence of a crowd that included several Brazilian faithful, including the country's vice-president, Hamilton Mourão, and Paolo Vilotta, the postulator for her canonization.
During her life, Sister Dulce dedicated herself to serving the poor, the sick and the most needy, and developed an important social work in her home state of Bahia, where she founded several charity hospitals and a social support system which she directed until his death, on 13 March 1992 at the age of 77.
Her canonization comes 27 years after her death, the third-fastest process in recent history after Pope Saint John Paul II (nine years after his death) and Saint Teresa of Calcutta (19 years).
The process began in 2000 when the Brazilian nun was considered a "servant of God." Nine years later, Pope Benedict XVI granted her the title of "venerable".
He beatified her in 2011.
( With inputs from IANS )