The OA Team

Founded in 2018, O’Neill Associates brings together a hand-picked team of like-minded lawyers and support staff who find creative solutions to each client’s unique problems.

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Garth O’Neill

Law Society of Ontario Certified Specialist (Labour Law)

Called to the Bar in 1991

  • Certified Specialist (Labour Law)
  • Labour Relations & Employment Law
  • Administrative Law (including claims before the Human Rights Tribunal of Ontario)
  • Alternative Dispute Resolution (ADR)
  • Human Resource Planning and Implementation

Garth O’Neill is one of the most well known and respected labour and employment lawyers in Northwestern Ontario and is recognized by the Law Society of Ontario as a Certified Specialist in Labour Law. Since 1991, Garth has advised many leading industrial and public-sector organizations throughout Northwestern Ontario on labour and employment law issues. He regularly represents management in contract negotiations and appears as counsel before the Labour Relations Board and Grievance Arbitrators, as well as at the Workplace Safety and Insurance Board (WSIB), Employment Standards, and Occupational Health and Safety proceedings.  Garth serves larger institutions as well as smaller companies and service-sector clients, and represents individuals in disputes with their employers.

Garth has completed comprehensive advanced training in facilitative mediation through the Stitt, Feld, Handy Group in Toronto, and adds ADR/mediation to the long list of services he offers his clients.

Garth believes in building strong, long-term relationships with clients. He regularly travels throughout Northern Ontario to serve his clients in their communities. Garth takes the opportunity, wherever possible, to commit to speaking engagements on workplace planning and management training for many of his clients. He often appears as a speaker and panellist at labour and employment law seminars in Thunder Bay and the region.

Community Involvement

Chancellor, Anglican Diocese of Algoma
Frequent Speaker and contributor at Human Resource conferences and events
Member, Private Pension Committee


LLB, Queen’s University, 1989

Elizabeth (Liz) McLeod

Associate Lawyer

Called to the Bar in 2016

  • Labour Relations & Employment Law
  • Administrative Law (including claims before the Human Rights Tribunal of Ontario)

Liz McLeod understands that the key to effective communication and productive working relationships is meeting everyone at the personal level. She is an attentive problem-solver and strives to provide her clients with practical legal solutions to equitably resolve conflicts and build productive, healthy work environments.

Liz is a proud member of the Charter class of the Bora Laskin Faculty of Law at Lakehead University in Thunder Bay. She gained practical advocacy experience both through participating in the Integrated Practice Curriculum and as a competitor at the Wilson Moot in 2016, a national debate competition that explores current constitutional issues facing women and minorities. Liz has advocated for clients in front of the Ontario Court of Justice, the Superior Court of Justice, the Ontario Labour Relations Board, Labour Arbitrators and the Human Rights Tribunal of Ontario since being called to the Bar. She advises clients in both federally and provincially regulated sectors with matters under both the Canada Labour Code and the Ontario Employment Standards Act.

Liz has previously worked in client service positions in the private and broader public sectors, and has travelled extensively around the world. These experiences have helped shape her well-rounded approach to law, and her ability to see issues from many sides. Liz is known for her professionalism and strong advocacy, her candour when needed, and her balanced, well-grounded counsel.

Community Involvement

Volunteer Coach, Thunder Bay Law Day
Volunteer, Lawyers Feed the Hungry Thunder Bay
Board Member, LEAF Thunder Bay (Women’s Legal Education and Action Fund)
Board Chairperson, Lakehead University Student Union (LUSU)
Board Member, Northern Spay Neuter Program


JD, Lakehead University, Bora Laskin Faculty of Law, 2016
Course Prize: Trust Law, 2016.

Hayley Yorke

Associate Lawyer

Called to the Bar in 2018

  • Labour Relations & Employment Law
  • Administrative Law (including claims before the Human Rights Tribunal of Ontario)

Hayley Yorke is a graduate of the Bora Laskin Faculty of Law where she was heavily involved in the growth and development of the school in its early stages. Hayley excelled at her studies in Bora Laskin, graduating with first-class standing. Her academics and oral performance earned her a place representing her school at the Wilson Moot in 2018, a national debate competition that explores constitutional issues.

Hayley has an eclectic range of work experience prior to her call – few lawyers can claim to have worked at Walt Disney World as Mickey and Minnie Mouse (and Piglet!). On a more serious note, Hayley has worked as a Legal Research Assistant, having researched the issue of Dementia and Human rights in partnership with the Ontario Dementia Advisory Group with the view of informing a shadow report to the United Nations under the Convention on the Rights of Persons with Disabilities, as well as researching complex poverty issues for Peterborough Social Services in housing stability and panhandler outreach.

Hayley believes volunteer work is an integral part of a lawyer’s commitment to their community. Hayley is the founding Membership Coordinator of the Thunder Bay Chapter of the Women’s Legal Education and Action Fund. Hayley has volunteered her time for the YWCA, the Humane Society, and the Dew Drop Inn.

Hayley’s Corgi, Mozzarella, has become our unofficial mascot – at least he thinks so!

Community Involvement

Founding Membership Coordinator, LEAF Thunder Bay (Women’s Legal Education and Action Fund)
Volunteer, Dew Drop Inn Soup Kitchen
President, Lakehead University Labour Law Association
VP Academic, Law Student Society
Mentor, Bora Laskin Faculty of Law Mentorship Program


JD, Lakehead University, Bora Laskin Faculty of Law, 2018

Warren Mouck

Associate Lawyer

Called to the Bar in 2016

  • Labour Relations & Employment Law
  • Administrative Law (including claims before the Human Rights Tribunal of Ontario)
  • Human Resource Planning and Implementation

Warren Mouck is a workplace lawyer who understands business.  His varied work background, from the warehouse floor to the retail counter to the Human Resources Department, makes him an intuitive and effective advocate in the Courtroom.

Warren provides strategic legal advice and representation to individuals, businesses and institutions on workplace law.  He is experienced in litigating wrongful dismissal claims, and has represented clients at all levels of Court in Ontario, including the Ontario Court of Appeal. Warren has conducted hearings at the Ontario Human Rights Tribunal, as well as matters before the Ontario Labour Relations Board, including union certification, employment standards and occupational health & safety matters.  Warren has industry experience in Human Resource Management, and provides practical advice on all aspects of the employment relationship.  He regularly conducts mediations, negotiates fair settlement terms, and advises on tax consequences of settling employment disputes.  Warren drafts employment agreements, and is knowledgeable in the areas of executive compensation and restrictive covenants.

Outside of the office, Warren’s hobbies include cycling, sailing Lake Superior, and skiing.  He has frequently returned to his Alma Mater, the Bora Laskin Faculty of Law, to speak about professionalism and substantive legal issues.  Warren’s talents also extend to barbershop quartet singing and his aspiring mastery of culinary arts.

Community Involvement

Board Member, Magnus Theatre
Annual Chair, TB Law Association Labour and Employment Continuing Legal Education
Volunteer, Dew Drop Inn


JD, Lakehead University, Bora Laskin Faculty of Law, Class Valedictorian, 2016
Graduate Certificate, Human Resource Management, Durham College, 2012

Rosanne Stasiewicz - Executive Assistant/Marketing Coordinator

Rosanne Stasiewicz

Executive Assistant/Marketing Coordinator

Rosanne Stasiewicz’s title only scratches the surface of her importance on the O’Neill Associates team. She has worked side by side with Garth O’Neill since 1996 as an indispensable point of contact for clients – with Rosanne, Garth really can be in two places at once. She is also invaluable behind-the-scenes developing documentation, reviewing files, working up files in preparation for arbitration, assisting at arbitrations, and drafting settlement documents.  As well, Rosanne is responsible for marketing O’Neill Associates by developing presentations, creating ads and brochures, overseeing all the firm’s charitable sponsorships and generally heading up community relations.

Rosanne herself is active in the community. She is one of the founding members of “Chairs for Chairity” and has participated or volunteered in many Thunder Bay events including the Dragon Boats races, Shelter House’s Corporate Relay, the Children’s Aid Society’s Hamper Program, and the Salvation Army Christmas Kettle.  She has fundraised for numerous local charities especially PRO Kids, and the Heart & Stroke Foundation.

Rosanne is known for her wicked sense of humour (a product of her environment, she claims) and her creativity in finding resourceful solutions to any problem. Her professionalism, dedication, and approachability are the embodiment of O’Neill Associates.

Karen Mercier - Law Clerk

Karen Mercier

Law Clerk

Karen Mercier brings with her nearly 40 years of legal experience, having worked in many areas of law including Labour and Employment, and Litigation matters. She is an IT, organizational and legal procedures guru, having trained countless junior and not-so-junior staff during her career. Her get-it-done approach ensures effective file and document management, and gives our clients great comfort in knowing their matters are well in-hand. Her professionalism and calming demeanour assists in the most stressful situations.

Legal worker by day, artist by night, Karen is a talented painter lending her time to various fundraising events. She enjoys working with acrylics as well as yarn art. A woman with many interests, her next goal will be mastering her electric ukulele.

Karen enjoys spending time with her family at their cottage on Lake Superior. With our office just a short walk up from Marina Park, watch out for her travelling to the office by boat, or paddle board, next summer. With Karen, you just never know!

Donna Kinnunen - Office Administrator

Donna Kinnunen

Office Administrator

Donna has more than thirty years’ experience in law firm administration. If an issue has arisen in the complex world of legal services, she has encountered it – and conquered it. Every now and then, you meet someone who has found a solution before you knew you had a problem. Donna is that person. With a calm demeanour and a wry sense of humour, Donna’s presence in the office brings still waters, and clients can be comforted in knowing she’s “on it”.

Donna is responsible for overseeing our administration functions in the office. She excels in customer service and is the friendly face who greets you when you arrive. Her administrative role includes various tasks such as file support, accounts payable, accounts receivable, data entry, payroll, and banking services.

With a passion for all that’s Northwestern Ontario, Donna particularly enjoys taking time to savour the tranquility of the outdoors. She has a zest for life like no other, and can always find reason to add a theme to the occasion. Her true passions in life are family and the time spent together, and community involvement.

Donna is a long-time supporter of local charitable organizations, and has left her mark on community events such as the Dragon Boat Festival, Corporate Relay, Chairs for Charity, Big Bike and the United Way, to name a few.