John Zephaniah Holwell FRS (17 September 1711 – 5 November 1798) was a surgeon, an employee of the English East India Company, and a temporary Governor of Bengal (1760). He was also one of the first Europeans to study Indian antiquities.
Holwell gained notoriety as a survivor of the Black Hole of Calcutta, June 1756. The Black Hole of Calcutta was the guard room in the old Fort William, at Calcutta, India, where troops of the Nawab of Bengal, Siraj ud-Daulah, held British prisoners of war after the capture of the Fort on June 19, 1756.
John Zephaniah Holwell claimed that following the fall of the fort, British and Anglo-Indian soldiers and civilians were held overnight in conditions so cramped that many died from suffocation, heat exhaustion and crushing. He claimed that 123 prisoners died out of 146 prisoners held. Doubt has been cast on both the numbers alleged and on whether the incident happened at all, and some modern historians have suggested the incident was fabricated by Holwell as a piece of propaganda to blacken the image of Siraj.
Howell’s account of this incident (1758) obtained wide circulation in England and some claim this gained support for the East India Company’s conquest of India. His account of the incident was not publicly questioned during his lifetime nor for more than a century after his death. However, in recent years, his version of the event has been called into question by many historians.
Born in Dublin, he grew up in London, and studied medicine at Guy’s Hospital. He gained employment as a surgeon in the English East India Company and was sent to India in 1732. He served in this capacity until 1749. In 1751, he was appointed as zemindar of the Twentyfour Parganas District of Bengal. He then served as a member of the Council of Fort William (Calcutta) and defended the settlement against Siraj Ud Daulah in 1756. He later succeeded Robert Clive as temporary Governor of Bengal in 1760, but was dismissed from the Council in 1761 for remonstrating against the appointment of Henry Vansittart as Governor of Bengal. He was elected Fellow of the Royal Society in 1767.
Holwell occupied a property on the site of what was later to become Mount Felix from 1760, residing there until 1769. The property then being sold to Charles Bennet, 4th Earl of Tankerville in 1772. 
 H.P. Bayon, “John Zephaniah Holwell (1711-1798) and the Black Hole of Calcutta” Proceedings of the Royal Society of Medicine 1944; Kohleun Adamson, Replacing Emotional Biases: A Critical Look at the Accounts of John Zephaniah Holwell, 2005; J. Dalley , The Black Hole: money, myth and empire, 2006.
 McCabe (1920) p. 357
 Bharater Itihas by Jibon Mukherjee
 Ellis; B. (2002). Walton Past. Ellis.