Adelaide of Vianden

Countess Adelaide of Vianden (d. 30 September 1376; German: Adelheid Gräfin von Vianden) was a countess from the House of Vianden, the cadet branch of the House of Sponheim that ruled the County of Vianden, and through marriage Countess of Nassau-Siegen. She acted as regent of the County of Nassau-Siegen for her eldest son in the period 1351–1362.
Adelaide is described as a clever and energetic woman, endeavoured to gradually settle the numerous feuds inherited by her and her son with the local noble families, the powerful lords of Bicken, Walderdorff and Haiger, although she herself did not disdain to take up the gauntlet forced upon her on one occasion or another. On the other hand, she also resolved many of the pledges entered into by her husband. In the underdeveloped County of Nassau-Siegen, where the local nobility thought they had a free hand, she kept the reins tight.