The 1984 summer Olympics in Los Angeles, California inspired Academic Decathlon founder Dr. Robert Peterson to make Academic Decathlon an international competition. Nationals in the United States remains open to international teams. The below list is possibly incomplete because the full list of Nationals participants is not available for most years before 2003 (1987, 1998, and 2001 are the only exceptions).
Countries Participating in Academic Decathlon
|Country||Most Recent Champion||Year(s) Participated|
|Canada||The Westside Miniversity||2004, 2016-present|
|China||Shanghai Foreign Language School Affiliated to SISU||2014-present|
|United Kingdom||Southbank International School, London||2009, 2011-present|