Sedulius Scotus (c. 840–860) was an Irish monk, teacher, Latin grammarian, and scriptural commentator who lived in the 9th century. During the reign of the Emperor Lothair (840–855), he was one of a colony of Irish teachers at Liège. His most important work was the book De Rectoribus Christianis, which he wrote to instruct the Emperor Lothair's son Lothair II on the proper way to rule as a Christian prince.
The Irish monks were widely known and respected on the continent for their great learning.