Maria Christina was the only child of Prince Carl Christian Joseph of Saxony, himself son of King August III of Poland, and his morganatic wife, Countess Franciszka Corvin-Krasińska. Her mother was created a princess (Princess Franziska Corvin-Krasińska) in her own right due to her marriage.
She was the Princess of Carignano and later Princess of Montléart by marriage. Her education was in the hands of several private tutors and governesses. She learned philosophy, geography, literatur, music, dance, and was taught several languages (German, Italian, French, Polish, and English).
They had two children: Charles Albert of Savoy-Carignano (2 October 1798 – 28 July 1849), King of Sardinia, who married Maria Theresa of Austria and had issue.
PPrincess Elisabetta of Savoy=Carignano (13 April 1800 – 25 December 1856), who married Archduke Rainer of Austria and had issue. On 1 February 1810 she was remarried in Paris to Julius Maximilian de Montléart, 6th Marquis de Rumont, 1st Prince de Montléart (1787–1865).
They had five children: Berthe Maria de Montléart (1811 – 1831), died young. Marguerite Julia de Montléart (1822 – 1832), died young.
Maria Christina died in Paris on 24 November 1851 at age 80.
7 December 1770 - 24 October 1797: Her Serrene Highness Duchess Maria Christina of Saxony.
7 December 1770 - 24 October 1797: Her Serrene Highness Duchess Maria Christina of Saxony 24 October 1797 - 16 August 1800: Her Highness Maria Christina, Princess of Carignano 16 August 1800 - 1 February 1810: Her Highness Maria Christina, Dowager Princess of Carignano 1 February 1810 - 24 November 1851: Her Royal Highness Maria Christina, Princess von Montléart
