Donald John is a first and middle name and may refer to:
Politicians
Donald John Trump (born 1946), 45th president of the United States
Donald John Trump Jr. (born 1977), son of Donald Trump
Donald John Bacon (born 1963), United States representative
Donald John Lee (1927–2011), former United States district judge
Donald John Bowman (1936–2013), Australian politician
Huan Donald John Fraser (1940–2010), Australian politician
Scientists
Donald John Markwell (born 1959), Australian social scientist
Donald John McGillivray (1935–2012), Australian botanical taxonomist
Donald John Wiseman (1918–2010), British archaeologist
Donald John Logan Bennet (born 1957), British archaeologist
Donald John Pinkava (1933–2017), American botanist
Donald John Lewis (1926–2015), American mathematician
Sportsmen
Donald John May (born 1946), American basketball player
Donald John Allan (born 1949), Australian cyclist
Donald John Deacon (1912–1943), Canadian ice hockey player
Donald John Bacon (born 1935), American MiLB player
Businessmen
Donald John Tyson (1930–2011), American businessman and CEO of Tyson Foods
Donald John Roberts (born 1945), Canadian-American economist
Military personnel
Donald John Dean (1897–1985), English recipient of the Victoria Cross
Donald John Stott (1914–1945), New Zealand soldier
Other
Donald John Cameron (1993–2016), New Zealand journalist
Donald John Smith (1926–2014), English priest