William (died 10 September 1056) was the Margrave of the Nordmark from 1051 until his death.
He was the eldest son and successor of the Margrave Bernard by a daughter of Vladimir the Great.
He died fighting the Slavs in the Battle of Pritzlawa.
Upon his death, he was succeeded by his half-brother Otto as Margrave of the Nordmark.
This article about a German margrave is a stub.