Cassels Brock & Blackwell LLP is pleased to announce the appointment of The Honourable Marco Mendicino as Senior Counsel & Strategic Advisor to the firm, effective November 3, 2025.
Mr. Mendicino brings more than two decades of legal and governance leadership to Cassels, and joins the firm to further expand its national advisory capacity as clients navigate evolving legal, regulatory, and geopolitical landscapes. Mr. Mendicino joins Cassels after serving as a federal prosecutor, Member of Parliament, Cabinet Minister, and most recently, Chief of Staff to Prime Minister Mark Carney.
“From his tenure as a federal prosecutor to his collaborative leadership experience and cross-sector insight in several notable parliamentary roles, Mr. Mendicino brings unique acumen, perspective and momentum to Cassels’ advisory team,” says Kristin Taylor, Cassels’ Managing Partner. “Mr. Mendicino’s appointment reflects Cassels’ commitment to delivering strategic advice that drives success in Canada’s most dynamic business sectors.”
As Senior Counsel and Strategic Advisor, Mr. Mendicino will work with Cassels’ leadership and clients across energy, infrastructure, technology, and trade sectors, helping to align business strategy with public-policy priorities, guide projects through complex regulatory environments, and strengthen partnerships between the private and public sectors.
“I’m honoured to be joining a national law firm with a proud tradition of legal excellence, a formidable reputation for helping clients grow their businesses, and an enduring commitment to Canada,” says Mendicino. “Cassels has long been recognized as one of the country’s best law firms, with top practitioners in energy, critical minerals, mining, cannabis, restructuring, Indigenous and reconciliation law, procurement, and artificial intelligence. Cassels is an ideal fit for me, where I can offer strategic counsel in a way that connects the law, business, and public purpose.”
As Chief of Staff, Mr. Mendicino led the Prime Minister’s Office through a national election and a historic transition of government. He oversaw the implementation of the government’s agenda, helped to build bipartisan support to pass major projects legislation, worked collaboratively with Premiers and Indigenous leaders, and closely advised the Prime Minister during international engagements at the White House, NATO, and Canada’s G7 presidency in Kananaskis.
Elected three times as Member of Parliament for Eglinton–Lawrence, he served as Ontario Caucus Chair and parliamentary secretary to Justice and Infrastructure. In Cabinet, Mr. Mendicino held the Immigration and Public Safety portfolios, representing Canada at the Five Eyes and G7 tables to strengthen cooperation on national security, cyber resilience, and combatting foreign interference, and human trafficking.
As a federal prosecutor, Mr. Mendicino litigated before both trial and appellate courts, and was assigned to high-profile anti-terrorism and national-security cases. He was elected as President of the Association of Justice Counsel, managed investigations at the Law Society of Ontario, and taught as an Adjunct Professor at Osgoode Hall Law School.
“We are thrilled to welcome Mr. Mendicino as Senior Counsel and Strategic Advisor to the firm,” says Noble Chummar, Cassels’ Deputy Managing Partner. “Mr. Mendicino has represented Canada at the highest levels of diplomacy at home and around the world. We are proud to bring his unique perspective, strategic insight and experience to our clients across Canada.”