Thor Longus or Thor the Long (fl. c. 1113 x 1124) is an early 12th-century Anglo-Saxon noble associated with Roxburghshire, a culturally English territory ruled by the Scottish king from the 11th-century onwards. A charter dating between 1107x1113 and 1124 claims that Thor the Long founded Ednam, previously a deserted waste granted to him by King Edgar of Scotland.
Ednam lies close to the Northumberland border with Roxburghshire. It states that he repopulated the settlement with his own followers and a church. The charter grants the church to the monks of St Cuthbert. There survives the notice of this grant given by Thor to his lord Earl David (future David I of Scotland), as well as Earl David's confirmation of the same grant.
Thor had a brother named Leofwine, mentioned in Thor's charter as requiring "redemption". Leofwine "the monk" was commemorated in the Martyrology of the Durham Cantor's book for June 2 (day of death), and in the same source Thor Longus was commemorated for May 14. The year of his death and descendants are not known, but Ednam appears in the crown's hand in 1136.
- Howlett, Caledonian Craftsmen, pp. 10–11; Lawrie (ed.), Early Scottish Charters, no. 24
- See Howlett, Caledonian Craftsmen, pp. 10–14 for text, translation and commentary; Lawrie (ed.), Early Scottish Charters, nos. 24, 33, 34
- Howlett, Caledonian Craftsmen, pp. 10–11; Lawrie (ed.), Early Scottish Charters, p. 259, suggests he had been a prisoner in the Crusades
- Barrow, "Scots in the Durham Liber Vitae", p. 111
- Lawrie (ed.), Early Scottish Charters, pp. 259–60, and no. 86
- Barrow, G. W. S. (2004), "Scots in the Durham Liber Vitae", in Rollason, David, The Durham Liber Vitae and Its Context, Woodbridge: Boydell Press, pp. 109–18, ISBN 1-84383-060-4
- Howlett, David (2005), Caledonian Craftsmanship: The Scottish Latin Tradition, Four Courts Press, ISBN 1-85182-485-5
- Lawrie, Archibald Campbell, ed. (1905), Early Scottish Charters : Prior to A.D. 1153, Glasgow: J. MacLehose and sons