Adalbert II of Ballenstedt (c. 1030 – 1076/1083), an early member of the House of Ascania, was Graf (count) in Saxony and Vogt of Nienburg Abbey.

According to the chronicler Lambert of Hersfeld, Adalbert supported Margrave Dedi I in his 1069 conflict with King Henry IV.

Dedi, a member of the House of Wettin, had married Adalbert's mother-in-law Adela of Louvain, widow since 1067, and claimed the Thuringian possessions of her deceased husband Margrave Otto of Meissen.

From 1072 on he participated in the Saxon Rebellion led by Count Otto of Nordheim and Bishop Burchard II of Halberstadt,[3] for which he was arrested after King Henry's victory in the 1075 Battle of Langensalza.

Even after his release about two years later, he backed the German anti-king Rudolf of Rheinfelden until he was finally killed, possibly in a feud, at Westdorf near Aschersleben by the Saxon noble Egeno II of Konradsburg.