A royal consort is the spouse of a ruling monarch. Consorts of monarchs in the Duchy of Brittany and its predecessor states had no constitutional status or power, but many had significant influence over their spouse. Listed are the wives of the Dukes of Brittany (some of whom claimed the title of King of Brittany) who were styled Duchesses of Brittany. Although there were six suo jure Duchesses of Brittany, the husbands of those duchesses were jure uxoris dukes and not consorts. Brittany is no longer a duchy and the title is currently not being used by the defunct Royal Family of France, so the position of Duchess of Brittany is vacant. Little is known about the duchesses whose husbands reigned prior to the year 900 besides their names.

Not all wives of the monarchs became consorts, as they may have died, been divorced, or had their marriage declared invalid prior to their husband's accession to the throne, or married him after his abdication. Such cases include

• Beatrice of England, the second daughter of Henry III, King of England; only wife of John II (as the Earl of Richmond), married 22 January 1260, died 24 March 1275.
• Marie, Viscountess of Limoges, the second daughter of Guy VI, Viscount of Limoges; first wife of Arthur II (as heir to the duchy of Brittany), married 1275, died 1291.
• Isabelle of Valois, the eldest daughter of Charles I, Count of Valois; first wife of John III (as heir to the duchy of Brittany), married 1297, died 1309.
• Yolande of Anjou, the youngest daughter of Louis II of Anjou, King of Naples; first wife of Francis I (as heir to the duchy of Brittany), married 1431, died 1440.
• Margaret of Burgundy, the third daughter of John the Fearless, Duke of Burgundy; first wife of Arthur III (as Lord of Parthenay and Duke of Touraine (later Constable of France)), married 10 October 1423, died 2 February 1441.
• Jeanne d'Albret, the daughter of Charles II, Count of Dreux; second wife of Arthur III (as Lord of Parthenay and Constable of France), married 29 August 1442, died 1444.

The succession was interrupted by the Norman occupation (907–937)

Picture	Name	Father	Birth	Marriage	Became Consort	Ceased to be Consort	Death	Spouse
	Ermengarde of Anjou [b][c]	Geoffrey I, Count of Anjou (Anjou)	-	973		after 982		Conan I
	Hawise of Normandy [b]	Richard I, Duke of Normandy (Normandy)	-	996		20 November 1008 husband's death	21 February 1034	Geoffrey I
	Bertha of Blois [b]	Odo II, Count of Blois (Blois)	-	-		1 October 1040 husband's death	11/13 April 1085	Alan III

Picture	Name	Father	Birth	Marriage	Became Consort	Ceased to be Consort	Death	Spouse
	Constance of Normandy [b][f]	William I of England (Normandy)	1061	1086		13 August 1090		Alan IV
	Ermengarde of Anjou [b][c][f]	Fulk IV, Count of Anjou (Anjou)	1068	1093		13 October 1119 husband's death	1 June 1146
	Maud FitzRoy [b][c][f]	Henry I of England (Normandy)	?	before 1113		17 September 1148 husband's death	after 1128	Conan III

Picture	Name	Father	Birth	Marriage	Became Consort	Ceased to be Consort	Death	Spouse
	Blanche of Navarre [g][h]	Theobald I of Navarre (Champagne)	1226	16 January 1236		11/12 August 1283		John I
	Yolande de Dreux, Countess of Montfort-l'Amaury [h]	Robert IV, Count of Dreux (Dreux)	1263	May 1292/4	18 November 1305 husband's accession	27 August 1312 husband's death	2 August 1330	Arthur II
	Isabella of Castile	Sancho IV of Castile (Anscarids)	1283	21 June 1310	27 August 1312 husband's accession	24 July 1328		John III
	Joanna of Savoy [g][i]	Edward, Count of Savoy (Savoy)	1310	21 March 1330		30 April 1341 husband's death	29 June 1344

Picture	Name	Father	Birth	Marriage	Became Consort	Ceased to be Consort	Death	Spouse
	Joanna of Flanders [g][i]	Louis, Count of Nevers (Dampierre)	1295	March 1329	30 April 1341 husband's accession	16 September 1345 husband's death	September 1374	John of Montfort
	Mary of England [i]	Edward III of England (Plantagenet)	10 October 1344	summer of 1361		1362		John IV
	Joan de Holland [g][i]	Thomas Holland, 1st Earl of Kent (Holland)	1350	May 1366		after 25 December 1384
	Joanna of Navarre [g][i]	Charles II of Navarre (Évreux)	1370	2 October 1386		1 November 1399 husband's death	9 July 1437
	Joan of France [i][j]	Charles VI of France (Valois)	24 January 1391	19 September 1396	1 November 1399 husband's accession	27 September 1433		John V
	Isabella of Scotland [i][j]	James I of Scotland (Stewart)	autumn of 1426	30 October 1442		18 July 1450 husband's death	13 October 1494/5 March 1499	Francis I
	Françoise d'Amboise [i][j][k]	Louis d'Amboise, Viscount of Thouars and Prince of Talmond (Amboise)	29 May 1427	June 1441/2	18 July 1450 husband's accession	22 September 1457 husband's death	4 November 1485	Peter II
	Catherine of Luxembourg-Saint-Pol [i][j][l]	Peter of Luxembourg, Count of Saint-Pol (Luxembourg-Saint-Pol)	?	2 July 1445	22 September 1457 husband's accession	26 December 1458 husband's death	1492	Arthur III
	Margaret of Brittany [i][m][n]	Francis I, Duke of Brittany (Montfort)	1443	16 November 1455	26 December 1458 husband's accession	25 September 1469		Francis II
	Margaret of Foix [i][m][n]	Gaston IV, Count of Foix (Foix)	1453	27 June 1471/4		15 May 1486
	Catherine de' Medici [i][o][p][q]	Lorenzo II de' Medici, Duke of Urbino (Medici)	13 April 1519	28 October 1533	10 August 1536 husband's accession	31 March 1547 Brittany ceased to exist	5 January 1589	Henry

• Countess of Dreux

• Marek, Miroslav. "Rulers of Bretagne". Genealogy.EU.^{[self-published source][better source needed]}