John Mortimer (1923–2009) was a British writer.
John Mortimer may also refer to: John B. Mortimer, Hong Kong judge Jack Cade, leader of the Kent rebellion John Mortimer (musician), in heavy metal band Holocaust John Mortimer (MP) for Northamptonshire John Robert Mortimer (1825–1911), archaeologist John Mortimer (agriculturalist) (1656–1736), English merchant and writer on agriculture John Hamilton Mortimer (1740–1779), British painter and printmaker John Jay Mortimer (1933–2013), American financier
See also Johnnie Mortimer (1931–1992), British television scriptwriter
John Mortimore (disambiguation)