After graduating from university, Jackson began her career as a research officer at the Centre for Socio-Legal Studies, a research institute of the Faculty of Law, University of Oxford. In 1991, she was elected a Fellow of St Catharine's College, Cambridge and appointed a lecturer in law. She then moved to Birkbeck College, University of London where she was a lecturer in law from 1993 to 1997. In 1998, she joined the London School of Economics for the first time having been appointed as a senior lecturer in law.