John Mostowich

Senior Legal Counsel


Common Law



Bar call:

Aberta (1993), Ontario (2022)



Dispute Resolution and litigation management

Employment and human resources

General Commercial

M&A and Divestitures

Practices in:


, Canada

, Ontario


John Mostowich

Senior Legal Counsel

Who is he

A self-described expert generalist, John Mostowich is experienced in many areas of corporate and commercial law. He has extensive experience resolving all kinds of disputes in and out of court, though these days he focuses on non-litigation matters and assisting clients to navigate the challenges of day-to-day business.
His decades of experience appearing before all levels of court often come in handy in analyzing issues and distilling these for clients. Clients love his practical and direct approach, and the fact that nothing fazes him. What’s more, he has little patience for anyone who wastes other people’s time and money. “Sometimes you have to ask yourself, how much law do you really need?” he says. “Businesses today need legal services that are economical, fast and reasonable.” In other words, you can count on John to frame his legal advice for the actual world, and what really matters.
Being a lawyer is just half of John’s story. In his other guise, he is a history buff and loves traveling, so he decided to combine the two by writing a travel guide to the battlefields of France, published in 2020. He’s already putting together plans for sequels.

How he got here

A law graduate of the University of Victoria, John started out as a lawyer for the Department of Justice, focusing primarily on commercial and civil litigation, before moving into private practice. Over the years, he developed a varied dispute resolution and business advisory practice in British Columbia and Alberta. His experience encompasses everything from commercial work and business acquisitions to a wide variety of contract claims and employment matters. A man of many skills, John took a hiatus from the law while living in Mexico City to pursue writing. In 2021 he moved to Stratford, Ontario, to resume practice, joining Simplex Legal as Senior Legal Counsel.

John Mostowich

Interview with John Mostowich

Please take a moment and provide me with a few examples of activities, hobbies you enjoy participating in.

Travel, writing (published author under pen name JD Mosteau), skiing, mountain biking.

Write about a personal or professional achievement you are proud of.

Published first book: "Footsteps of Generals-A Travel Guide to the Battlefields of France". Successfully transitioned legal practice from 100% litigation to a solicitor practice.

Why did you decide to join us at Simplex?

After winding down my practice in 2019 in order to pursue writing interest, I found I missed the law and so decided to resume a part-time practice in 2021. Simplex is a good match for my legal interest.

What is it about Simplex's model do you believe is most attractive and beneficial to our clients?


John would love to hear from you