Admiral James Vashon was a British officer of the Royal Navy. He saw service during the Seven Years' War, the American War of Independence and the French Revolutionary and Napoleonic Wars. He was first captain of HMS Dreadnought, between 1801 and 1802. Previously, he had commanded Alert (1781), Europa (1786), and Formidable.

HMS Dreadnought was a Royal Navy 98-gun second rate. This ship of the line was launched at Portsmouth at midday on Saturday, 13 June 1801, after she had spent 13 years on the stocks. She was the first man-of-war launched since the Act of Union 1800 created the United Kingdom of Great Britain and Ireland, and at her head displayed a lion couchant on a scroll bearing the Royal arms as emblazoned on the Standard.