What does Crawley MacKewn Brush actually do?

It's a Toronto litigation firm focused on securities and corporate commercial disputes. That includes regulatory investigations and enforcement proceedings before the OSC and CIRO, shareholder and corporate governance disputes, securities class actions, and related commercial, insurance, and product liability litigation.

I've been contacted by the OSC or CIRO about my registration. Can this firm help?

Yes. The firm's lawyers regularly represent registrants and market participants in regulatory investigations and enforcement proceedings before the Ontario Securities Commission and the Canadian Investment Regulatory Organization, and its CMB Registrant Services arm advises registered firms on compliance on an ongoing basis.

What is CMB Registrant Services, and is it different from the law firm?

CMB Registrant Services is a related but separate offering for securities industry registrants. Rather than one off litigation, it provides ongoing compliance support such as monitoring regulatory developments, handling regulatory inquiries, training, and advice on conflicts of interest and anti-money laundering obligations, generally on a monthly retainer.

Does the firm handle securities class actions?

Yes, securities class action defence is one of its core practice areas, alongside broader shareholder and corporate governance disputes.

How big is Crawley MacKewn Brush, and where is it located?

The firm has grown from a small securities litigation practice founded in 2005 to roughly 20 to 24 lawyers, all working out of a single office at 179 John Street in downtown Toronto.

Does the firm only work with big public companies, or does it take employment cases too?

Its main focus is securities and corporate commercial litigation for public companies, investment dealers, and registrants, but it also handles employment litigation, particularly disputes involving departing brokers and executives in the financial services sector.

Crawley MacKewn Brush LLP | LawOnline Directory

About Crawley MacKewn Brush LLP

Crawley MacKewn Brush LLP is a Toronto litigation firm built around securities and corporate commercial disputes. The firm traces to 2005, the year Matthew Scott joined as its first associate, and it has grown from that small start to about 20 to 24 lawyers today, all working from one office at 179 John Street. The name reflects three founding partners, Alistair Crawley, Melissa MacKewn, and Robert Brush, who each came to the firm with securities backgrounds: Crawley from litigating disclosure and market conduct cases, MacKewn from a stint as Senior Enforcement Counsel at the Ontario Securities Commission, and Brush from capital markets and director and officer liability work.

The firm's practice covers regulatory investigations and enforcement proceedings before the OSC and the Canadian Investment Regulatory Organization, shareholder and corporate governance disputes, securities class actions, and broader commercial litigation, including insurance and product liability matters and employment disputes involving financial services clients. It also runs CMB Registrant Services, a separate advisory arm that helps registered securities firms with day to day compliance, regulatory filings, and training rather than courtroom disputes. Chambers Canada has placed the firm in Band 1 for securities litigation, and Benchmark Litigation Canada has named it Securities Litigation Firm of the Year in multiple years.

Practice areas

Civil Litigation & Dispute Resolution

Business & Corporate Law

Administrative & Regulatory Law

Class Actions

Milestones & recognition

Founded in 2005, growing from a small securities litigation practice to about 20 to 24 lawyers by the mid-2020s.
Benchmark Litigation Canada has named the firm Securities Litigation Firm of the Year in multiple years, including 2026.
Chambers Canada ranks the firm in Band 1 for securities litigation.
Alistair Crawley was inducted into the Benchmark Litigation Canada Hall of Fame.
Alistair Crawley is a Fellow of the Litigation Counsel of America and supervises the Osgoode Investor Protection Clinic.
Melissa MacKewn previously served as Senior Enforcement Counsel at the Ontario Securities Commission before joining the firm and now co-chairs the OSC's Litigation Assistance Program.

In the community

A partner supervises the Osgoode Investor Protection Clinic at Osgoode Hall Law School, which gives law students hands on experience helping investors.
A partner co-chairs the Ontario Securities Commission's Litigation Assistance Program.
Firm lawyers act as skills instructors and faculty for The Advocates' Society, training other litigators.

Good to know

Wheelchair accessible A calendar with a checkmark beside a clock

By appointment

Lawyers 20

This firm’s lawyers at a glance

Called to the bar: 1983–2025 · median 13 years in practice 20 of 20 lawyers
Law schools: Queen's University (4), University of Toronto (3), Osgoode Hall Law School (2), University of British Columbia (2), Western University (2), Columbia Law School and 6 more 20 of 20 lawyers

Who handles what

The neighbourhood

The firm's office sits at 179 John Street, in the Grange Park area of downtown Toronto.

That location puts a securities and commercial litigation firm within easy reach of the Ontario Securities Commission and the courts its lawyers appear before, without the firm needing a second office. Rather than serving walk-in local clients, CMB works with public companies, investment dealers, and registrants across Canada, and downtown Toronto is simply where that work concentrates.

Frequently asked questions

What does Crawley MacKewn Brush actually do?: It's a Toronto litigation firm focused on securities and corporate commercial disputes. That includes regulatory investigations and enforcement proceedings before the OSC and CIRO, shareholder and corporate governance disputes, securities class actions, and related commercial, insurance, and product liability litigation.
I've been contacted by the OSC or CIRO about my registration. Can this firm help?: Yes. The firm's lawyers regularly represent registrants and market participants in regulatory investigations and enforcement proceedings before the Ontario Securities Commission and the Canadian Investment Regulatory Organization, and its CMB Registrant Services arm advises registered firms on compliance on an ongoing basis.
What is CMB Registrant Services, and is it different from the law firm?: CMB Registrant Services is a related but separate offering for securities industry registrants. Rather than one off litigation, it provides ongoing compliance support such as monitoring regulatory developments, handling regulatory inquiries, training, and advice on conflicts of interest and anti-money laundering obligations, generally on a monthly retainer.
Does the firm handle securities class actions?: Yes, securities class action defence is one of its core practice areas, alongside broader shareholder and corporate governance disputes.
How big is Crawley MacKewn Brush, and where is it located?: The firm has grown from a small securities litigation practice founded in 2005 to roughly 20 to 24 lawyers, all working out of a single office at 179 John Street in downtown Toronto.
Does the firm only work with big public companies, or does it take employment cases too?: Its main focus is securities and corporate commercial litigation for public companies, investment dealers, and registrants, but it also handles employment litigation, particularly disputes involving departing brokers and executives in the financial services sector.

Where to find them

Suite 800 - 179 John Street, Toronto, Ontario, M5T 1X4 · 416-217-0110

Similar firms in City of Toronto

Cambridge LLP

46 lawyers · Est. 2010

Cambridge LLP is a litigation firm with offices in Toronto, Vancouver, Burlington, Barrie, and Elliot Lake. It focuses on business and commercial litigation, cross-border and international disputes, estates litigation…

Civil Litigation & Dispute Resolution

Wills, Estates & Trusts

Construction Law

Class Actions

Tupman & Bloom LLP

13 lawyers

Tupman & Bloom LLP is a national litigation boutique focused on estate, trust, and appellate advocacy disputes, with offices in Toronto, Halifax, and Vancouver. The firm represents executors, trustees, and beneficiari…

Wills, Estates & Trusts

Civil Litigation & Dispute Resolution

Personal Injury

Administrative & Regulatory Law

Miller Thomson LLP

28 lawyers

Miller Thomson LLP is a national, full-service business law firm with offices across Canada. Its lawyers work in corporate and commercial law, litigation, real estate, construction, insurance, tax, labour and employme…

Business & Corporate Law

Civil Litigation & Dispute Resolution

Construction Law

Insurance Law

Listing compiled from the firm’s public website in August 2026. Verify licence status in the Law Society of Ontario directory ↗