The first Adelaide Festival of Ideas was held in 1999 (July 9 - 11) and explored the themes of reconciliation; ethics and the law; democracy, survival and cooperation and speakers participated in such sessions as Democracy, Survival and Co-operation, Life, The Universe and Everything and Hello Dolly: cloning, ethics and the law.

The Adelaide Festival of Ideas 2001 (July 12 - 15) explored the themes of water; population; addiction/intoxication; reconciliation and cosmology. Speakers participated in such sessions as RIP: Reconciliation in Paralysis?; Good Drugs, Bad Drugs - the human face of addiction; Has science abolished God? and The 21st Century: How much water, how many people? Award-winning Canadian journalist Naomi Klein and Director of Care Australia and former Prime Minster of Australia (1975-83) Malcolm Fraser were amongst the forty-five Australian and overseas speakers appearing.

The theme of the 2003 Adelaide Festival of Ideas (July 10 - 13) was Hope and Fear. It explored themes of theology, the Middle East, ethics, arms control, human rights, globalisation, child health, justice, migration and the search for extra terrestrials. Featured speakers included: George Monbiot (UK), non-conformist political commentator; Ziauddin Sardar (UK), Muslim scholar and cultural critic; Elisabeth Schussler Fiorenza (USA), Harvard University Professor of Scripture and Interpretation; Fiona Stanley, child health specialist and Australian of the Year; Robert Manne, Professor of Politics, La Trobe University; Richard Butler, renowned arms control expert and Stephanie Dowrick, writer and psychotherapist.

The 2005 Adelaide Festival of Ideas (7-10 July) posed the age old question of 'What is to be done?' A rallying point for revolutionaries and clerics, this theme was chosen as past Festivals brought forward an appetite amongst audiences for putting ideas into action. Adelaide played host to 50 thinkers and activists from across the world including author, academic and feminist; Germaine Greer (UK), Muslim cleric and spokesman; Iman Feisal Abdul Rauf (USA), evolution biologist, futurist, author and speaker; Elisabet Sahtouris (USA/Greece), Professor of Law and Indigenous Studies; Larissa Behrendt (AUST), long time member of the Women's Electoral Lobby and senior lecturer at the University of Technology; Eva Cox (AUST) and a host of other intellectuals, civic minded business people, social entrepreneurs, discoverers and teachers.