Countess Matilda of Vianden was a noblewoman from the House of Vianden, a prominent family in the medieval region of Luxembourg. She lived during the 12th century and is known for her role in the political landscape of the time, particularly in relation to the Holy Roman Empire. Matilda was married to Henry I, Count of Luxembourg, which strengthened the ties between their families. Her lineage and marriage alliances contributed to the influence of the Vianden family in European politics, making her a significant figure in the history of the region.