Sister Teresita, from the Basque Country in northern Spain, died on Tuesday night at the Roman Catholic convent Buenafuente del Sistal in the center of the country.
She was buried at the convent on Wednesday.
Sister Teresita had entered the convent in the municipality of Guadalajara on April 16, 1927, when she was 19.
She left the convent only once in the following 86 years, on August 20, 2011, during Roman Catholic youth celebrations, to meet with visiting Pope Benedict XVI, who was born on the same day she had joined the convent.
That meeting, held at the Vatican’s nunciature in Madrid, was “very short but very emotional,” the convent’s abbess, Sister Maria, told AFP.
During her long stay in the convent, Sister Teresita held posts of abbess, prioress and mistress of novices.
“She was very lucid and healthy but she got weaker because age does not forgive,” said the abbess.
Sister Teresita lived “an exemplary life,” she added.