Jagot was born in England, and migrated to Australia with her family in 1968. Jagot studied at Baulkham Hills High School before receiving an arts degree from Macquarie University in 1987. She subsequently received a law degree with first-class honours from the University of Sydney in 1991. At her Federal Court swearing in ceremony, it was remarked that during her time at university "she appears to have won every available prize in law." She had won the Butterworths Prize for Most Proficient in First Year, the Pitt Cobbett Prize for Administrative Law, the Sir Alexander Beattie Prize in Company Law, the Margaret Ethel Peden Prize in Real Property, the Minter Ellison Prize in Intellectual Property, and the Nancy Gordon Smith Prize for Honours."Swearing in of Judge Jayne Jagot", Attorney-General's Department (NSW). Accessed 21 April 2009. (2006 Winter) Bar News: Journal of the NSW Bar Association 71.
