After a brief period as a solicitor in Brisbane, Brandis was called to the Queensland Bar in 1985 where he practised until entering politics in 2000. Brandis developed a commercial practice with a particular emphasis on trade practices law. He appeared as junior counsel in the High Court of Australia in the equity case "Warman v Dwyer". He was also the junior barrister for the plaintiff in the long running "Multigroup Distribution Services v TNT Australia" litigation in the Federal Court of Australia.