Widdecombe is the daughter of a Ministry of Defence civil servant James Murray Widdecombe and Rita N Plummer. She attended the Royal Navy School in Singapore, and a convent school in Bath. She then read Latin at Birmingham University and later attended Lady Margaret Hall, Oxford, to read Philosophy, Politics and Economics (PPE). She worked for Unilever (1973–75). She was then an administrator at the University of London (1975–87) before entering Parliament.