Alwyn Ruddock (1916–2005) was a noted British historian of the Age of Discovery, best known for her research on the 'English' voyages of the 15th-century explorer John Cabot. Cabot and other English navigators of the time were trying to find lands to the West, such as the mythical 'Isle of Brasil' or the North American lands first discovered by Icelanders in previous centuries.
Ruddock's first published research was a two-volume work (With David Beers Quinn) on The Port Books or Local Customs Accounts of Southampton (Vol I 1937 & Vol II 1938). During World War II, she taught in the history department of what was to become Southampton University. She also published in many of the top academic journals, such as English Historical Review, Economic History Review, and History.
In 1946 Ruddock moved to Birkbeck College, University of London where she published in 1951 Italian Merchants and Shipping in Southampton, 1270-1500 (1951). She was appointed the position of reader in history in 1952, and subsequently elected as a fellow of both the Society of Antiquaries of London and of the Royal Historical Society.
In the 1950s and early 1960s, Ruddock's concerns shifted from the activities of Italian merchants in Southampton to a broader investigation of Italian mercantile networks and businesses in medieval Europe. She intended to produce a 'big' book on Italian Merchants and Shipping. Around 1965, she claimed to have made a discovery in the archives of a Venetian banking family: documents relating to John Cabot's early activities, including a loan that the family advanced to him in c. 1496. For at least 25 years, she was promising to produce her Cabot book 'soon'; in 1992 she undertook a formal book contract with the University of Exeter Press.
She felt unable or unwilling to publish it; upon her death, she left instructions for her research papers to be destroyed. Her only published research in this field are a number of short articles that she wrote in the late 1960s and early '70s.
After her death, the Bristol University historian Dr Evan Jones began to investigate Ruddock's unpublished research claims about the voyages of John Cabot, producing an article about them in the journal Historical Research in April 2007 (print edition, 2008). He wrote a second article about two documents found by the historian, Margaret Condon, who had not published them in the 1980s, in part due to the understanding that Ruddock had a book in progress on the topic. Evan Jones subsequently set up The Cabot Project along with a number of other historians in Britain, Italy, Canada and Australia to carry out further investigations into evidence of the early voyages and to search for the evidence for Ruddock's claims. 
- 'Salazar's account of Bristol's discovery of the Island of Brasil (pre 1476)'
- 'E. T. Jones, 'Alwyn Ruddock: "John Cabot and the Discovery of America "', Historical Research, 81, (May, 2008), 235-6'; 'E. T. Jones, 'The Quinn papers: transcripts of correspondence relating to the Bristol discovery voyages to North America in the fifteenth century', 13-17.'
- 'Jones, 'Alwyn Ruddock'. See also 'Obituary Alwyn Ruddock' by Emma Mason, The Guardian, Friday 17 February 2006
- A. A. Ruddock, ‘John Day of Bristol and the English voyages across the Atlantic before 1497’, Geographical Journal, cxxxii (1966), 225–33; ‘The accounts of John Balsall, purser of the Trinity of Bristol, 1480–1’, ed. T. F. Reddaway and A. A. Ruddock, in Camden Miscellany XXIII (Camden 4th ser., vii, 1969), pp. 1–28; A. A. Ruddock, ‘Columbus on Iceland: new light on an old problem’, Geographical Journal, cxxxvi (1970), 177–89; A. A. Ruddock, ‘The reputation of Sebastian Cabot’, Bulletin of the Institute of Historical Research, xlvii (1974), 95–9.
- 'Jones, 'Alwyn Ruddock'
- 'E. T. Jones, 'Henry VII and the Bristol expeditions to North America: the Condon documents', Historical Research (Early View, August, 2009)'; 'The lost voyage: First English-led expedition to North America' Press release issued 27 August 2009 University of Bristol; 'King's letter reveals epic voyage'
- Guidi-Bruscoli, F. (2012), John Cabot and his Italian financiers. Historical Research (Accessed May 2012)
- Gugliotta, Guy (June 19, 2012). "Discovery of a £16 Advance Sheds Light on John Cabot’s Adventures". The New York Times. pp. D3.