A Reputation of Caring for Our Clients.
Genuine Personalized Attention.

We have a proven track record of success covering four decades. During that time, we have built a solid reputation for providing personalized care and attention, while getting the best possible outcomes for our clients. We welcome the opportunity to help our clients with their legal issues and over the years we have acquired the legal knowledge and experience needed to successfully represent them. Many of our clients tell us that we have a "human touch" that makes them feel comfortable dealing with us. And we take that as a high compliment..


Our Core Values Are Reflected in
How We Care for Our Clients.

Compassionate, caring, sensitive, honest, knowledgeable, approachable, integrity, personable; just a few of the words used by our clients to describe our law firm. And underlining everything we do is a sincere desire to work hard to ensure that the legal system works for you and not against you. We love getting testimonials from our clients as it affirms why we do what we do, each and every day.


A General Law Practice
With Expertise in Estate Litigation.

We are committed to providing our clients the highest quality legal services with the greatest degree of personal attention in areas of Estate Litigation, Wills and Estates, Civil Litigation, Business Law, and Real Estate. We are sensitive to the need of each individual client and strive to make the legal process as smooth as possible. Our lawyers are professional advocates with problem-solving skills benefiting individual and business clients.  


More Than Four Decades Of Knowledge
and Experience On Your Side.

Let us put our knowledge and experience to work for you. Our legal team has decades of combined legal experience, and every client receives the benefit of having direct access to an extraordinary depth of legal talent. We value customer service, legal integrity, and confidentiality and seek to uphold those values in our professional practice. When our clients come to us, they know that we "have their back" and that we will work hard on their behalf.

Helping Our Community
With Their Legal Needs.

We are a local firm with roots in our community that go deep; this is where we live, work and play. Where we "serve our community" by providing individuals and businesses with excellent legal services. It is where we have earned a reputation throughout the Peel Region's legal communities for standards of excellence in representing the interests of clients from all walks of life.

Two Generations of Experience.

The father and son team of John and Tim Lockhart. John was called to the bar in 1977, after taking his law degree at the University of Toronto, while his son Tim was called to the Bar in January of 2013 after receiving a Juris Doctor from Bond University, in Queensland, Australia. John has long practiced in the area of litigation, an area of law that Tim is also focusing on and benefiting from his father's experience and knowledge.

Our Practice Areas

Proudly Serving Peel Region Since 1978.

The Tannahill, Lockhart & Clark Law team has a combined legal experience of close to 150 years. We are proud of our history serving the legal needs of businesses and residents across Peel Region and of our reputation for personalized legal representation, caring and respect. When you work with our team, you can be confident in our ability to actively represent you and we always pursue the best course of legal action for your particular needs. You are not just another file at TLCL. We are a law firm that genuinely cares about the well-being of our clients.


Blog Articles

6 Feb
First, it was seat belts, then it was impaired driving, now, distracted driving. There are many forms of distracted driving that can arise in motor vehicle accident litigation. During the examination for the discovery process there will be questions posed by lawyers on both sides about whose fault the accident was. Experienced trial lawyers, such...
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5 Feb
With over 90,000 flights taking off every day around the world and billions of passengers flying internationally every year, aviation technology has come a long way since the Wright brothers. Unfortunately, there is a cost for global travel that goes well beyond the airline ticket itself. What happens when passengers are injured or worse,...
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6 Jan
Who needs a Litigation Guardian? Unfortunately, serious injuries can happen to anyone, including individuals who would legally be considered to be “parties under a disability”. A “party under a disability” is a person who does not have the legal capacity to instruct legal counsel. This includes infants, children, young adults under the age of...
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Case Studies

29 Jun
Our clients, who we will call the Smiths*, were befriended by a man we will call Sam*. Sam got involved deeply in the Smiths’ lives, seeking to help them in matters of business, real estate, and spiritual matters. Sam gained the Smiths’ trust to point where they considered him a close friend and confidante....
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13 Feb
Our client, who we will call Bob* owned a family cottage property with his Aunt, with two cottages being on the same piece of land. Both Bob and his aunt enjoyed each other’s company and shared expenses of the joint piece of land over the years. The Greedy Son Eventually, Bob’s aunt started to...
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29 Jun
Our client, who we will call Doug, was cleaning the BBQ that he bought from a National Retailer one night. After about 20 seconds of cleaning the BBQ, some metal from the BBQ flew up into his eye. He went to the hospital that night and medical care providers removed a piece of metal...
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29 Jun
The client, who we will call Rosie*, suspected that her sister had been using a Power of Attorney to take money from her father’s account before he died. However, her sister was named as estate trustee under the Will and refused to provide any information. Rule 75.06 : Order to Compel Information We consulted...
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Our Team

Douglas D. Tannahill

Senior Partner
Doug Tannahill has practiced law in Brampton since being called to the bar in 1975. Doug completed his undergraduate degree at Ashland University in Ohio before taking his law degree at Osgoode Hall.  He practices in the area of Corporate and Commercial law, with an emphasis in the area of Corporate and Commercial Agreements, including Commercial Real Estate and Leasing....
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John S. Lockhart

Senior Partner
John Lockhart was called to the bar in 1977, after taking his law degree at the University of Toronto, and his undergraduate degree at the University of Guelph. John started his career at the firm of West & Robb in Brampton where he met Doug Tannahill. They became partners in 1978. John carries on a general practice with an emphasis...
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Tyrrell (Terry) Clark

Senior Partner
Terry Clark has been a lawyer since 1977. He took his undergraduate degree at McMaster University and graduated from the University of Toronto Law School in 1975. After his call in 1977, Terry worked in the City Solicitor’s Office at the City of Mississauga until 1981, working solely in the area of Municipal Law and Land Development. Building upon his...
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Timothy S. Lockhart

Tim was called to the bar in 2013 and has a broad-based civil litigation practice, including estate litigation, real estate litigation, commercial litigation, and construction lien actions. Tim’s non-litigation practice includes commercial and residential real estate, wills and estates, and charity law. Tim uses a personal touch with all his clients and is always personally available to take clients through...
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Olga Wagner

Office Manager
Olga Wagner has been with Tannahill Lockhart & Clark since 1988. Olga began her career with the firm as our receptionist. Her professional manner and engaging voice and smile have been long time attributes to the TLC Family. In 2007 Olga became the Office Manager, continuing to manage the telephone and reception area while carrying out the day to day...
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Leilani Hawkins

Senior Law Clerk, Litigation, Wills and Estates
Leilani Hawkins is a Senior Law Clerk who has been with our firm since 1991. She works in the areas of Litigation and Wills and Estates. After attending Ryerson in their Business Management Course, Leilani began her career in Toronto, and came to work with Tannahill, Lockhart & Clark when she relocated to Brampton, and then Georgetown with her husband...
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Sonja Syme

Senior Law Clerk, Real Estate/Wills and Estates
Sonja is a Senior Law Clerk at Tannahill, Lockhart & Clark and is responsible for significant commercial and industrial sales and purchases, land development projects and the purchase and sale of large tracts of vacant land. She also processes the sale of homes in residential subdivisions for home builders whom we represent. Although her particular expertise is dealing with unusual...
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Eleanor Mairs

Senior Law Clerk, Real Estate/Wills/Estates
Eleanor Mairs joined Tannahill, Lockhart & Clark in 1994.  After graduating from Sheridan College, Legal Secretarial Program, Eleanor worked in the legal field prior to joining our firm.  Eleanor is the legal assistant to Douglas Tannahill and is responsible for Corporate and Commercial matters, Real Estate and Wills and Estates.  Her areas of expertise are in the preparation of Multiple...
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Don't Hesitate to Contact Us!

Because law can be a complicated matter. It can cause you a big problem if you ignore it. Let us help you today so you are prepared for tomorrow!

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