Sister Candida Bellotti said the secret to a long life was to "love, love and keep on loving with joy."
The nun, who has seen 10 popes and 57 Italian Prime Ministers take office in her lifetime, celebrated her birthday at a convent in the Tuscan town of Lucca.
Pope Francis sent her his personal birthday wishes.
In the message, the Catholic leader said he "shared the joy of the happy celebration and sent congratulations and heartfelt wishes."
The pair met at the Vatican on her 107th birthday.
Sister Candida became a nun in 1931 and worked as a nurse in hospitals across the country.
The nun said that her life ambition has been fulfilled by working with convents.
"Throughout my life, I have always thought to myself: Where God puts me, that is the right place for me," she said.
Despite her age, Sister Candida is not the oldest Italian nun.
Sister Marie-Josephine Gaudette, born in America but living in Rome, is five years her senior.