|Joan of Savoy|
|Duchess consort of Brittany|
|Tenure||21 March 1330–30 April 1341|
|Died||29 June 1344 (aged 33–34)|
église des Cordeliers, Dijon
|Spouse||John III, Duke of Brittany|
|House||House of Savoy|
|Father||Edward, Count of Savoy|
|Mother||Blanche of Burgundy|
Joan of Savoy (1310 – 29 June 1344), was Duchess consort of Brittany, wife of John III, Duke of Brittany. Joan was also a claimant to the County of Savoy upon the death of her father. She was a member of the House of Savoy and married into the House of Dreux. Joan was born in 1310, she was the only child of Edward, Count of Savoy, and his wife, Blanche of Burgundy.
Joan married in 1329 aged nineteen to the forty-three-year-old, childless John III, Duke of Brittany; she was his third wife, John's second wife Isabella had died the previous year.
The same year as Joan's marriage, her father died. Being his only child she considered herself his successor. However, Savoy had never had a female ruler, leading to a dispute in the succession. Joan's uncle Aymon had the support of the nobles of Savoy for the Semi-Salic inheritance and succeeded as count.
John supported Joan's rights on Savoy. After the marriage, Joan renewed her claim on Savoy and allied herself with the Dauphin de Viennois against her uncle. By agreement settled by the French King  on 22 November 1339, she renounced her rights of succession in return for an annual income of 6000 livres.
Joan and John were married for twelve years but produced no offspring, and John died on 30 April 1341, leaving Joan a childless widow. This led to a disputed succession in Brittany between John's half-brother of the same name and John's niece Joan.
In 1343, when her uncle Aymon died, Joan renewed her claim on the county of Savoy against her nine-year-old cousin, Amadeus VI. In her will, she left the county to Philip, Duke of Orléans to spite her cousins. In the end, he negotiated a similar settlement to the one of Joan, yielding the claim in exchange for 5000 livres annually.
Joan died on 29 June 1344.
- Cox, Eugene L. (1967). The Green Count of Savoy. Princeton, New Jersey: Princeton University Press. LCCN 67-11030.