John Thornton was an English cartographer in the second half of the 17th century. He called himself Hydrograph to the Hudson Bay Company and the East India Company, but there is no evidence of his activity for the companies. In 1677 he entered into a partnership with John Seller together with William Fisher, John Colson and James Atkinson, which lasted only until 1679. Thornton and his colleague took over much of Seller's business. After Thornton's death in 1708, his son Samuel took over the business, but he died shortly afterwards and the stock was finally taken over by Mount and Page.
In Thornton's name the following atlases appeared among others:
- The English Pilot. The Third Book, 1703-11
- The English Pilot. The Fourth Book, 1689
- Atlas Maritimus, 1685, 1700, 1708.
- Hydrographia Galliae: The Sea Coasts of France, 1695