John Holker (1719 – 27 April 1786) was a Jacobite soldier, industrialist, and one of the world's first industrial espionage agents, born in Stretford, England, to blacksmith John Holker and his wife Alice.
He married a local woman, Elizabeth Hilton, in 1740, and while still in his twenties, he set up a calendering business in Manchester, in partnership with Peter Moss.
When Bonnie Prince Charlie's army entered the town in 1746, both men purchased commissions in the Jacobite regiment that was raised there.
Holker and Moss were captured at Carlisle during the army's retreat, and were incarcerated in Newgate Prison, in London.
They succeeded in escaping together, and Holker made his way, via Holland, to France, where he joined the Scottish Ogilvy Regiment, a Jacobite regiment in the French army, seeing service in Flanders.Holker and his wife became French citizens in 1766.