John Doubleday (about 1798 – 25 January 1856) was a British craftsperson, restorer, and dealer in antiquities who was employed by the British Museum for the last 20 years of his life. He undertook several duties for the museum, not least as a witness in criminal trials, but was primarily their specialist restorer, perhaps the first person to hold the position. He is best known for his 1845 restoration of the severely-damaged Roman Portland Vase, an accomplishment that places him at the forefront of his profession at the time.