She was born and educated in New Zealand, graduating with an LLM from The University of Otago. After lecturing in law at Otago, she moved to England to teach law at Southampton University and then at King's College, University of London, where she was also Director of the Anglo French Law Degree (Sorbonne), the first joint degree in Europe.

In 1989, Judith entered private practice as an employment lawyer with law firm, Titmuss Sainer Dechert and in 1994 moved to law firm, Wilde Sapte, to become their Director of Education and Training. From 2000-2003 she was Special Adviser to the Chairman at Clifford Chance, the world's largest law firm.

Judith was a Board Member of Birkbeck College, University of London from 1993-2003 and was Chair of Governors from 1999-2003. She was also a Board Member of London Guildhall University from 1992-2002, a member of the Court and Council of Imperial College, University of London from 2001-2003, and Provost of King's College Cambridge from 2003-2006. She is currently Chairman of The Independent Schools Council and has been a Governor of the Sir John Cass Primary School, the City of London School for Girls, Senior Fellow of Eton and on the Council of Gresham College. She is a Governor of Westminster School and Westminster Abbey Choir School.

From 1986, Judith was closely involved in the running of the City of London. She was a member of the Court of Common Council until 2004 and sat on many committees of the Corporation of London including chairing the Education Committee. From 1996-2003 she was Chairman of the Policy and Resources Committee. This effectively made her the leader of the Corporation of London, the body which governs the "square mile", London's financial district. During her time in the city she was a board member of International Financial Services, London, The City Disputes Panel, London First, The London First Centre and she was deputy Chairman of the 4Ps. In 2000 she became finance and business adviser to the Mayor of London and was Vice Chair of the London Development Agency and chaired its Business and Skills Committee until July 2004. She also chaired the Private Investment Commission for London. In 2003 she was made a vice president of London First. She is Chairman of The New West End Company.

"Dame Judith's career and her considerable public and voluntary activity made her an ideal person to take this role for the first time." - Professor Muriel Robinson, University College Principal

She was a Governor of The English Speaking Union, a Trustee of the Geffrye Museum, The British Museum Development Trust, and The Natural History Museum. She is a trustee of The Imperial War Museum.

She was the Chairman of The Royal Opera House from 2003 to 2008.

In 2005 she was appointed a member of The Equality Commission which reported to the Prime Minister in 2007. She was an international member of the Diversity Advisory Board for Merrill Lynch and she was on the main Board of Merrill Lynch & Co. Inc. from 2006 to 2008.

She is a Fellow of Birbeck College, The London Business School and City & Guilds Institute. She has been awarded Honorary Doctorates in Laws by The University of Otago, The City University and London Metropolitan University.