John Calvert may refer to:
- John Calvert (1726–1804), British politician, MP for Tamworth, Wendover and Hertford
- John Calvert (died 1844) (c. 1758–1844), British politician, MP for Tamworth, Huntingdon, St Albans and Malmesbury
- John Calvert (mine owner) (1812–1890), Yorkshireman who came to South Wales as a civil engineering contractor and became an important developer of the Rhondda coalfield
- John Calvert (magician) (1911–2013), American magician
- John Calvert (radio executive), radio commercials producer and voiceover artist
- John Calvert Griffiths, attorney general of Hong Kong
- John Calvert (scholar), American scholar of Islamism at Creighton University