Gavin Devonald Roynon (26 April 1936 – 2 March 2018) was an English first-class cricketer, teacher and military historian.

Roynon was born at Sutton in April 1936.^[1] He was educated at Charterhouse School, before going up to Worcester College, Oxford where he studied modern languages.^[2] While studying at Oxford, he made his debut in first-class cricket for Oxford University against the touring New Zealanders at Oxford in 1958. He made eight further first-class appearances for Oxford, all coming in the 1958 season.^[3] He scored 188 runs in these matches, at an average of 14.46 and a high score of 58.^[4] In addition to playing first-class cricket while at Oxford, Ronyon also played minor counties cricket for Oxfordshire between 1954–58, making five appearances in the Minor Counties Championship.^[5] While at Oxford he was an accomplished rackets player, gaining a blue in the sport.^[1]

After graduating from Oxford, he became a history teacher at Eton College, a position he held until his retirement in 1999.^[6] Following his retirement he wrote several books on history, mostly on the subject of the First World War, including the publishing of three diaries from individuals involved in the war.^[1][6] He died following a four-year-long illness in March 2018.^[7] He was survived by his wife, five children and fifteen grandchildren.^[1]