|Catherine of Brunswick-Lüneburg|
|Electress consort of Saxony|
|Tenure||6 January 1423 – 4 January 1428|
|Died||28 December 1441 (aged 45–46)|
|Spouse||Frederick I, Elector of Saxony|
|Issue||Frederick II, Elector of Saxony|
William III, Duke of Luxembourg
|House||House of Welf|
|Father||Henry the Mild, Duke of Brunswick-Lüneburg|
|Mother||Sophie of Pomerania|
As a 7-year-old she married on 7 February 1402 Margrave Frederick IV "the Warlike" of Meissen (1370–1428), who in 1425 became the first Elector of Saxony, as Frederick I. The elector lost a large part of his army in the Hussite Wars in a battle in 1425 at Most. During Frederick's absence, Electress Catherine organized another army of 20,000 men, which rushed to Frederick's aid, but was defeated devastatingly in the Battle of Aussig in 1426.
Catherine spent time with her husband, but more frequently alone, at Mildenstein Castle in Leisnig, which thereby developed into a private residence of the Saxon Electors.
She is buried in the Princely Chapel in Meissen Cathedral.
From her marriage Catherine had the following children:
- Catherine, died young;
- Frederick II, Elector of Saxony (1412 – 1464);
- Sigismund, Bishop of Würzburg, (3 March 1416 – 24 December 1471);
- Anna, (5 June 1420 – 17 September 1462), married to Louis I, Landgrave of Hesse;
- Catherine, (1421 – 23 August 1476, Berlin), married to Frederick II, Elector of Brandenburg;
- Henry, (21 May 1422 – 22 July 1435);
- William III, Duke of Luxemburg (1425 – 1482), Landgrave of Thuringia, Duke of Luxemburg; married
- in 1446, Anne of Austria (1432–1462)
- in 1463, Catherine of Brandenstein († 1492)