Bishop Johannes Rudbeckius or Bishop Johannes Rudbeck (1581–1646), bishop at Västerås, Sweden, from 1619 until his death, and personal chaplain to King Gustavus II Adolphus ("the Great").
In his capacity of bishop he was restlessly active in organising. He founded the Swedish system of public personal register, ordering his parsons to file comments on every person in the parish. In 1623 he founded the first gymnasium, a school of secondary education, in Västerås, but he also took care to introduce a rough kind of compulsory schooling for all children in his diocese.
Rudbeckius was considered politically suspect by his superiors but his reforms were gradually introduced in the whole country.
With his second wife Magdalena Hising, he had a son Olaus Rudbeckius, Sr., who was to become the most important Swedish scientist of the 17th century. Bishop Rudbeckius' granddaughter, Wendela Rudbeck, married Peter Olai Nobelius, from whom descends Alfred Nobel.
Bishop Rudbeckius is also notable for calling what is now known as the Dalecarlian horse "the Devil's plaything."