Margaret O'Sullivan's practice involves all aspects of private client work, including estate planning; will and trust planning; incapacity planning;
estate dispute resolution, advising executors, trustees and beneficiaries and administration of estates and trusts. Prior to establishing an
independent practice, Margaret was a partner in the Toronto office of the national Canadian law firm Stikeman Elliott where she directed its
trusts and estates practice. She has practiced exclusively in the area of trusts and estates since 1983.
Margaret is recognized in The Best Lawyers in Canada 2019, Legal Week's Private Client Global Elite 2018, in the 2018 Edition of The Canadian
Legal Lexpert Directory, in Who’s Who Legal: Private Client 2018, and in Who’s Who Legal: Canada 2018 as one of the five leading trust and
estate lawyers in Canada. She is ranked at the highest ranking of Band 1 in Chambers High Net Worth Guide 2018. She is the recipient of the
2014 STEP Founder’s Award for Outstanding Achievement, the Ontario Bar Association’s 2013 Award of Excellence in Trusts and Estates Law
and the 2008 STEP Canada Volunteer of the Year Award.
Margaret is a founding member and a former Deputy Chair of the Society of Trust and Estate Practitioners (Canada) and former Chair of the
Editorial Board of its newsletter STEP INSIDE. She is a past Deputy Chair and a member of the Board of Directors and Council for STEP
Worldwide as well as a past Chair of the Professional Standards Committee. She is a past Chair of the Trusts and Estates Section of the Ontario
Bar Association and a past elected member of the Ontario Bar Association Council (1993–98). She is an Academician of The International
Academy of Estate and Trust Law, as well as a current member of the Canadian Bar Association, the American Bar Association, the New York
State Bar Association, the International Bar Association, and the Canadian Tax Foundation. She was elected a Fellow of the American College
of Trust and Estate Counsel in 1995 and elected a member of the STEP Cross Border Estates Global Steering Committee in 2017. Margaret is
also a member of the Queen’s University Gift Planning Advisory Committee.