Sigeferth (or Sigefrith) (died 1015) was, along with his brother Morcar, described by the Anglo-Saxon Chronicle as "chief thegn of the Seven Burghs".
According to the 12th century chronicle of John of Worcester, Sigeferth and Morcar were the sons of one Earngrim who is otherwise unrecorded.
The Seven Burghs of which they were said to be the chief men are believed to have been the Five Burghs—Derby, Leicester, Lincoln, Nottingham and Stamford—together with Torksey and York.
Sigeferth was murdered alongside his brother Morcar by Eadric Streona at Oxford in 1015.
Edmund redistributed some of the lands that had previously belonged to Sigeferth.