John Barker may refer to:
Business
John Barker (advertising executive) (born 1965), founder of Barker/DZP
John Barker (businessman) (1847–1925), Australian
John H. Barker, American businessman, owner of the John H. Barker Mansion in Michigan City, Indiana
Politics
John Barker (died 1589) (c. 1532–1589), MP for Ipswich
John Barker (died 1618) (1579–1618), MP for Shrewsbury
John Barker (Bristol MP) (died 1636), English politician
Sir John Barker, 4th Baronet (1655–1696), English MP for Ipswich
John Barker (diplomat) (1771–1849), English diplomat and horticulturist
Sir John Barker, 1st Baronet (1840–1914), founder of Barkers department store in Kensington, London, and Liberal MP John Barker (MP for Ilchester), English merchant and politician John Barker (Parliamentarian), English draper and politician, MP for Coventry John Barker (parliamentary officer) (1815–1891), clerk of the colonial Victorian (Australia) parliament John Barker (Australian politician) (born 1947) John Barker (Philadelphia) (c. 1746–1818), Mayor of Philadelphia, Pennsylvania from 1807 to 1810 and 1812–1813 John Barker (Kansas politician) (born 1951), member of the Kansas House of Representatives John Barker, author and member of the militant group The Angry Brigade
Religion
John Barker (minister) (1682–1762), Presbyterian divine
John Barker (Master of Christ's College, Cambridge) (1728–1808), priest and academic John Barker (priest) (1912–1992), Dean of Cloyne
Sports
John Barker (Australian footballer) (born 1975), for Hawthorn, Brisbane Lions, and Fitzroy John Barker (English footballer) (1948–2004) John Barker (Scottish footballer) (1869–1941)