Koulla E. Roussos was admitted into legal practice in 1995. From 1995-1997 she was engaged as a summary prosecutor with the NT Director of Public Prosecutions. From 1997-2004 she worked as a criminal defense lawyer with the NT Legal Aid Commission and across all in Indigenous legal services in the Northern Territory  (NAAJA; KRALAS, CAALAS) appearing in all jurisdictions including Children’s Court, Magistrates Court and Supreme Court matters in trials, contests, bail applications, appeals, and sentencing. From 1998-2000 she was responsible for coordinating one of Australia’s largest test case and politically significant litigations (Cubillo & Gunner v. The Commonwealth– the Stolen Generation litigation case).

She was the Principle Legal Officer at Fitzroy Legal Service in 2003-2004. From 2004-2010 she has held various roles with Victoria Legal Aid including Deputy Managing Lawyer VLA Ballarat from 2006-2010. In 2005 she was accredited by Law Institute of Victoria as a Criminal Law Specialist. 

She signed the NT Bar Roll in 2012, and has appeared in all NT Court jurisdictions, including in trials, pleas, contests, bail applications and appeals. She has appeared in NT Teacher’s Board Disciplinary Inquiry.  In 2014 she was junior to George Georgiou SC appearing in the Royal Commission into Institutional Responses to Child Sexual Abuse. In 2017 she represented two individuals in the NT Royal Commission into Youth Detention.

 In 2018 she signed the Victorian Bar Roll and appears regularly in Magistrate and County Court matters across metropolitan, suburban and regional courts in Victoria and Northern Territory.