Sieg Eiselen is professor in Private Law at the University of South Africa, Pretoria. He lectures in general contract law, unjustified enrichment law, international commercial law and information technology law. He holds a doctorate of law in contract law from the University of Potchefstroom. He is an NRF B rated researcher. He has a litigation practice in commercial law and has been a member of the Johannesburg Bar since 1999.
He is co-author with Albert Kritzer of Pace Law School, New York, of the International Contact Manual Volumes IV and V (Thomson West). He is also co-author of Information Technology Law (LexisNexis) and co-author with Tjakie Naudé of Commentary on the Consumer Protection Act (2015 Juta). He has published widely on general South African contract law, unjustified enrichment law, international trade law and harmonisation, information technology law and consumer credit law. He was the Rapporteur for CISG Advisory Council Opinion No 13 Inclusion of Standard Terms under the CISG.
He has been the Secretary of the CISG Advisory Council since 2007.