The Team

Our founding partners are Andrew Williams, Mark Williams and Marie O’Toole – learn about their skills and experience below, or contact us to speak directly with any of our staff members.

Andrew is the senior founding partner at Williams Barristers and Solicitors. Formerly a criminal Barrister and Solicitor with another Adelaide leading criminal defence firm, he brings a wealth of experience to the practice. Andrew holds a LLB/LP (Hons) from Flinders University of South Australia and has been admitted to Practice in the High Court of Australia, the Supreme Court of South Australia and the High Court of Solomon Islands. He is a member of the Legal Services Commission Complex Criminal Law Panel (Counsel & Solicitor) as well as the Law Society of South Australia.

Andrew has previously worked as a Prosecutor with the Office of the Director of Public Prosecutions, an International Legal Adviser to the Solomon Islands Government assisting Restoration of Law and Justice Processes and Institutions following a civil war, and has 22 years experience as a Police Officer. He has also tutored at Flinders University Law School. Andrew’s breadth of experience means you get the benefit of in-depth legal and investigative knowledge, advocacy and negotiation skills. Andrew has a focus on defending criminal and traffic matters and providing strong representation for each client.

Call Williams Barristers and Solicitors Adelaide on 08 8451 9040 to make an appointment with Andrew.

Mark is a founding partner of Williams Barristers and Solicitors. His principal areas of practice are Criminal Law, Wills and Estates, and Traffic Law. Mark holds a LLB/LP and BIntSt from Flinders University of South Australia and is a member of the Law Society of South Australia and the Legal Services Commission General Panel.

Mark has developed a broad range of skills and knowledge through his work in private firms in Adelaide and through working with the Aboriginal Legal Rights Movement and Office of the Director of Public Prosecutions in the Solomon Islands. Having represented clients in criminal, family and probate matters in South Australia, Western Australia, New South Wales and Queensland, Mark possess a wealth of legal and procedural knowledge.

Mark applies his experience and knowledge to achieve the best possible outcome for his clients whether that be in the Magistrates Court, District Court or Supreme Court.

He is also well versed in the drafting of Wills, Estates, Power of Attorney, and Advance Care Directives and in assisting clients to make applications to the Supreme Court for grant of Probate and Letters of Administration.

With his calm, confident and considered approach, Mark will achieve the best possible result for you and your family while always treating you with dignity and respect.

Call Williams Barristers and Solicitors Adelaide on (08) 8451 9040 to make an appointment with Mark.

Rebecca is a senior lawyer who specialises in Family Law. She has a wealth of experience in all matters falling under the jurisdiction of the Family Law Act and is a qualified Collaborative Lawyer. She has worked in the legal industry since 2006, completing her Bachelor of Laws (LLB) with Honours in September 2015. Rebecca is admitted to practice in the High Court of Australia and the Supreme Court of South Australia. She is also the Chair of the College of Law’s Curriculum Advisory Committee.

This year she was proudly recognised as a ‘Rising Star’ in Family Law in Doyles Guide, identifying her ability to operate at a high level professionally and technically in Family, Divorce, Parenting, and Matrimonial Matters.

Rebecca is passionate about assisting her clients to navigate the legal landscape to achieve positive outcomes for them in a respectful and dignified way. Her interest in family law was sparked when she was a child, brought up by a single parent after her parents separated. As a result, she saw the court process unfolding and has a deep understanding of the emotional stresses upon parents and children when a family unit breaks down. She is driven to resolve matters without litigation however when required she will engage in litigation and has significant experience representing clients in the Federal Circuit and Family Court of Australia and the Adelaide Magistrates Court.

Rebecca also has significant experience conducting private Mediations, Family Dispute Resolution Conferences, Court Ordered and Informal Conferences, and Collaborative Practice. Utilising these processes align with her enthusiasm for obtaining positive and realistic outcomes for her clients in an empathetic and efficient manner.

Rebecca is dedicated to professional development and education within the legal industry. In addition to her current position as Chair of the College of Law’s Curriculum Advisory Committee, she served on the Women Lawyer’s Association of South Australia for three years. She is also a longstanding member of the Law Society of South Australia and the Family Law Section of the Law Council of Australia.

If you have a family law issue, you should contact our office on (08) 8451 9040 to make an appointment with Rebecca.

Danielle is a valued member of our Family Law Team and has worked in the legal industry since 2021.

Danielle was admitted to practice in the Supreme Court of South Australia in 2023 and the High Court of Australia in 2024.

Prior to commencing practice as a family lawyer, Danielle acquired extensive practical experience working for the Courts Administration Authority in both criminal and care and protections jurisdictions.

Danielle’s interest in family law was sparked when she volunteered at the Women’s Legal Service supporting vulnerable women facing extreme legal challenges. Danielle’s passion for family law was later cemented through her experience working as a law clerk within a family law practice.

Danielle is passionate, client focussed and possess a strong desire to achieve positive outcomes for clients either through negotiation or, if necessary, litigation.

Call Williams Barristers and Solicitors on (08) 8451 9040 to make an appointment with Danielle.

Courtney graduated from the University of South Australia with a Bachelor of Laws with Honours in early 2022. She went on to undertake a Graduate Diploma in Legal Practice with the Law Society of South Australia and is admitted as a Barrister and Solicitor in both the Supreme Court of South Australia and the High Court of Australia. Courtney is also a Member of the Legal Services Commission General Panel.

Prior to commencing her Legal Studies, Courtney enlisted into the Royal Australian Air Force in order to assist and support everyday people. While this path was cut short, Courtney saw no better way to make an impact on people’s lives then to commence a career in advocacy. This passion lead to Criminal Defence law.

Courtney has experience working on a wide array of criminal and traffic matters, which she obtained while working as a Criminal Law Clerk, and then Solicitor at another prominent South Australian Defence firm. It was in this position that Courtney was able to obtain valuable insight into criminal and traffic law, and her true passion for criminal defence quickly grew. During this time, Courtney’s desire to help in assisting clients navigate through their legal matters emerged.

Call Williams Barristers and Solicitors Adelaide on (08) 8451 9040 to make an appointment with Courtney.

Katherine Gariboli is our friendly and welcoming Senior Administrator.  In a return to the legal industry she joined the Williams team in 2024.  Katherine  brings a wealth of experience and expertise gained from her previous work within the legal industry as well as a wider rage of businesses and professions.  She has always enjoyed working within team environments and assisting clients with their enquiries.  As the Williams Legal front of house Katherine continues to utilise her administrative skill set and display he warmth and welcoming nature as you enter our office.

Marie is a founding partner of Williams Barristers and Solicitors.

Marie holds a M Ed, B Ed and Dip T. She brings a range of management expertise to the firm from broad experience in executive positions and educational leadership. As first point of contact in our office, Marie will make sure you are able to quickly access the legal support you need in a friendly and no nonsense manner.