John or Jack Ross may refer to:

• John Ross (author) (1957–2022), American author of the 1996 novel Unintended Consequences
• John F. Ross (author), American historian and author
• John Ross (publisher), printer and publisher in 19th century Newcastle
• John Ross (artist) (fl. 1996), British comic book artist
• Jack Ross (musician) (1916–1982), rock and roll singles in 1962
• Jack Ross (writer) (born 1962), New Zealand poet and novelist
• John Ross Ewing III, character in the TV series Dallas
• John A. Ross (composer) (1940–2006), African American jazz musician, composer and choral conductor
• John Ross, former drummer of Hostage Calm

• John Ross of the Inner Temple (1563–1607), English barrister and poet
• John Wesley Ross (1841–1902), American attorney in Washington, D.C.
• Sir John Ross, 1st Baronet (1853–1935), Irish judge and Unionist politician
• John Rolly Ross (1899–1963), U.S. federal judge
• John William Ross (1878–1925), U.S. federal judge
• John Wilson Ross (1863–1945), justice of the Supreme Court of Arizona
• John Andrew Ross (born 1954), Missouri judge

• John Ross (American patriot) (1726–1800), figure in the American Revolution
• John Lockhart-Ross (1721–1790), admiral of the British Royal Navy
• John Ross (British Army officer, died 1809) (1744–1809), British Army officer
• John Ross (Royal Navy officer) (1777–1856), British naval officer and Polar explorer
• John E. Ross (1818–1890), fought in the Modoc War
• John Ross (VC) (1822–1879), Scottish corporal of the British Army during the Crimean War
• John Ross (British Army officer, born 1829) (1829–1905), British commander
• John Ross (British Army officer, died 1843), lieutenant governor of Guernsey
• John Buchan Ross (1912–2009), British Royal Air Force officer
• Jack Ross (Australian soldier) (John Campbell Ross, 1899–2009), Australian veteran of the First World War
• John H. Ross (1918–2013), pilot during World War II

• John Ross (representative) (1770–1834), U.S. representative from Pennsylvania
• John Ross (Cherokee chief) (1790–1866), principal chief of the Cherokee Nation
• John Ross (Canadian politician) (1818–1871), Canadian senator from Ontario
• John Sylvester Ross (1821–1882), miller and political figure in Ontario
• John Ross (Nova Scotia politician) (1822–1892), political figure in Nova Scotia, Canada
• John Jones Ross (1831–1901), Canadian politician from Quebec
• J. Gordon Ross (1891–1972), Liberal party member of the Canadian House of Commons
• John Ross (New South Wales politician) (1891–1973), member of the New South Wales Legislative Assembly
• J. R. Campbell (communist) (1894–1969), British communist activist and newspaper editor
• John N. Ross (1920–2011), Irish solicitor and politician
• John Ross (activist) (1938–2011), American author, journalist, and activist
• John Ross (Victorian politician) (1940–2003), member of the Victorian Legislative Council
• Jack Ross (Arizona politician) (1927–2013), Arizona car dealer, philanthropist and politician
• John Q. Ross (1873–1922), lieutenant governor of Michigan

• John Ross (bishop of Carlisle) (died 1332), English bishop of Carlisle
• John Ross (bishop of Exeter) (1719–1792), English bishop of Exeter
• John Ross (missionary) (1842–1915), Scottish missionary to Northeast China

• John Ross (American football) (born 1995), American football player
• John Ross (curler) (born 1938), Canadian curler
• Jack Ross (footballer, born 1892) (1892–1973), Australian rules footballer for Geelong between 1920 and 1922
• Jack Ross (footballer, born 1895) (1895–1943), Australian rules footballer for Geelong in 1919
• Jack Ross (footballer, born 1911) (1911–1996), Australian rules footballer for Collingwood
• Jack Ross (footballer, born 2000), Australian rules footballer for Richmond
• Jack Ross (footballer, born 1976), Scottish professional footballer
• John Ross (rower) (1945–2009), Canadian rower in the 1968 Summer Olympics
• John Ross (rugby union) (born 1967), Australian rugby player
• John Ross (runner) (1931–2022), Canadian Olympic athlete
• John Ross (tennis) (born 1964), professional tennis player

• John Ross, 1st Lord Ross (died 1501), Scottish nobleman
• John Ross, 2nd Lord Ross (died 1513), Scottish nobleman
• John Ross (explorer) (1817–1903), explorer of Central Australia
• Charles Rawden Maclean (1815–1880), known as John Ross, sea captain and opponent of slavery
• John W. Ross (Iowa architect) (1830–1914), architect in Davenport, Iowa
• John W. Ross (North Dakota architect) (1848–1914), architect in Grand Forks, North Dakota
• John Ross (businessman) (1840–1876), Scottish retail businessman
• J. K. L. Ross (1876–1951), Canadian industrialist from Montreal
• John Ross (chemist) (1926–2017), American physical chemist
• John R. Ross (born 1938), American linguist
• John Ross (blogger) (fl. 1980s), British far-left blogger
• John Merry Ross (1833–1883), Scottish academic author and teacher

• John Ross House (disambiguation)
• S. John Ross (disambiguation)