- 28 June
- 25 October as one of the Forty Martyrs of England and Wales
- 29 October as one of the Martyrs of Douai
Studied and was ordained at the English College, Douai, France. he returned to England on 13 October 1619 to minister to covert Catholics. Arrested and condemned to death for his faith in Lancashire in 1627; he was held in various prisons, at one point hearing the final confession of Saint Edmund Arrowsmith just before that martyr was led to the gallows. Through the intercession of Queen Henrietta Maria, he and fifteen other priests were turned over to the French ambassador on 11 April 1630 to be sent into exile in France.
Soon after, Father John returned to England, working with Saint Henry Morse. They worked tirelessly and fearlessly with the sick during a plague outbreak in 1636. He was arrested again for his faith in Westminster on 28 November 1637. Held in various prisons until 16 July 1640 when he was released due to the mitigating circumstances of his good works.
Arrested again on 2 December 1640; he pled guilty to the crime of priesthood, and was condemned to death. After 14 years in prison, during which he ministered to any prisoners who showed interest, he was executed by orders of the Commonwealth under Oliver Cromwell. One of the Forty Martyrs of England and Wales.
- hanged, drawn, and quartered on 28 June 1654 at Tyburn, London, England
- remains purchased by the Spanish ambassador to England, and sent to the English College in Douai, France
- the relics were hidden to prevent destruction during the French Revolution, were rediscovered in 1927, and are now housed at Westminster Cathedral, London
- “Saint John Southworth“. Saints.SQPN.com. 12 January 2015. Web. 6 March 2015. <>