John Rennie is the name of the following people:
* John Rennie the Elder (1761–1821), engineer (factories, canals, ''design'' of London Bridge)
* John Rennie the Younger (1794–1874), engineer (rail lines, ''completion'' of London Bridge)
* John Rennie (naval architect) (1842–1918), naval architect
* John Rennie (MI6 officer) (1914–1981), Director of MI6
* John Rennie (soccer) (born c. 1944), American soccer coach
* John Rennie (editor) (born 1959), editor-in-chief of ''Scientific American'', 1994–2009
* John Rennie (cricketer) (born 1970), Zimbabwean Test and ODI cricketer
* John Gillies Rennie (1904–1952), Quebec politician and educator
* John Rennie (GC) (1920–1943), British recipient of the George Cross
* John Shaw Rennie (1917–2002), Commissioner-General for United Nations Relief and Works Agency for Palestine Refugees in the Near East
* John T. Rennie (1824–1878), Scottish ship-owner
{{hndis, Rennie, John