| William | |
| Death Date: | 10 May 1074 |
| Feast Day: | 2 September |
| Venerated In: | Roman Catholic Church |
| Titles: | Bishop |
William of Roskilde (Danish: Vilhelm, German: Wilhelm, Latin: Wilhelmus; died 8 May or 10 May) was a Danish prelate of the Roman Catholic Church who served as the Bishop of Roskilde in Denmark from about 1060.
Nothing is known about William's early life. A contemporary historian, Adam von Bremen, recounts him as a cleric serving Archbishop Adalbert of Bremen before becoming bishop of Roskilde, which suggests a German descent. While the Gesta Danorum by Saxo Grammaticus written a century later frames him as Anglo-Saxon who previously served Cnut the Great in England as his priest and clerk.
The sources around William's tenure as bishop are scarce. He is attributed with initiating the construction of Roskilde Cathedral that his successor completed in around 1080.
According to Saxo Grammaticus, William had a close relationship with King Sweyn II that allowed him to secure valuable land and power for his bishopric. He also retells an appropriated fictional story based on a legend with Saint Ambrose and Theodosius I originally written by Paulinus the Deacon about murder and penitence to explain their relationship development.
William's death is commonly recorded on either 8 May or 10 May and around year 1074 because evidence suggest that he died before King Sweyn II as the king selected his successor after he had passed. William's remains were buried in Roskilde Cathedral.
William of Roskilde's date of canonization is unknown, but his memorial is observed by the Roman Catholic Church on September 2.