Edward John Jackett, known as John Jackett, (4 July 1878 – 11 November 1935) was an English rugby union player, who represented the England national rugby union team, the British Lions and competed in the 1908 Summer Olympics for Great Britain.
He was born in Falmouth, Cornwall and played for Falmouth RFC before emigrating to Kimberley in South Africa where he joined the Cape Mounted Police. He returned to Cornwall and became Cornish Cycling champion. He joined Leicester Tigers in 1904 and played 183 times for the club over the next 7 years. He also represented Cornwall 52 times. He was capped for England thirteen times between 1905 and 1909. He also played against the touring South Africa team on their 1906 tour of Great Britain and took part in the 1908 British Lions tour to New Zealand and Australia. Jackett was also a member of the Cornish rugby union team which, representing Great Britain, won the 1908 Olympic silver medal on 26 October 1908.
In 1911 Jackett moved north to manage a theater in Dewsbury and joined Dewsbury RLFC in rugby league, he was part of the 1912 Challenge Cup winning side.
He is the brother of Richard ″Dick″ Jackett.