Plat Simionati
Automatically compiled listing. Details may contain errors.Wellington County (Guelph)
One of 50 law firms listed in Guelph, and one of 21 handling Family Law.
About Plat Simionati
Plat Simionati is a Guelph law firm that practises family law and nothing else. Clients can get conventional legal advice and representation there, and they can also resolve things through mediation or the collaborative family law process.
Sean Plat and Taryn Simionati opened the firm in 2022, setting out to pool what each of them does well and give clients family law representation that's strong, practical and efficient. Both came from Miller Thomson LLP, where each had been a partner. Sean Plat's road there ran through Kearns McKinnon, which Sean joined in 1998 and which merged into Miller Thomson in 2003; Sean then spent 16 years as a partner at the national firm.
The two founders have deep roots in this work. Sean Plat, a Guelph native who studied at the University of Guelph before law school at Queen's University, was called to the bar in 1997 and has handled only family files for more than 25 years. Taryn Simionati has practised exclusively in family law since 2011. Associate Brittany Thompson was called to the Ontario Bar in 2019 after articling at Miller Thomson LLP, and the team also includes a law clerk, Clarissa Emmert, and an assistant, Daniela Lewis.
The office is at 258 Woolwich Street in Guelph, though the client base reaches well beyond the city: Taryn Simionati, who lives in Burlington, acts for people in Waterloo and Kitchener, Halton and Hamilton, and the Toronto, GTA and Peel area as well as Guelph.
Practice areas
Property, income and support
Taryn Simionati works on complicated income, property and equalization questions, along with child and spousal support. Sean Plat's practice also centres on complex property cases and support claims for both spouses and children.
Our guide: How to Get a Divorce in Ontario
Parenting disputes
Taryn Simionati handles decision-making responsibility and parenting time matters, and Sean Plat takes on parenting cases with a high level of conflict.
Marriage contracts and cohabitation agreements
Taryn Simionati drafts complicated marriage contracts and cohabitation agreements for clients of every kind, high net worth individuals included.
Mediation
Depending on the case, a mediation can bring in other professionals such as social workers, psychologists, parenting coordinators or accountants, and associate Brittany Thompson regularly attends mediations with clients to settle their matters.
Court proceedings
When a matter has to go to court, the firm can start an application for a client or answer one brought by the other side. Taryn Simionati has appeared in the Ontario Court of Justice, the Superior Court of Justice and the Court of Appeal, Brittany Thompson has appeared before the same three courts, and Sean Plat has advanced matters at every level of court in Ontario.
Good to know
Wheelchair accessible
By appointmentHow Plat Simionati works
Every new matter at Plat Simionati begins with a conversation about whether negotiation is likely to get that client to a fair outcome. If talks stall or the other side isn't being reasonable, the lawyers move to mediation, mediation/arbitration or a court proceeding instead. For high-conflict cases, the firm's commitment is to push hard for a result that's fair and just.
On marriage contracts, cohabitation agreements and separation agreements, the firm's policy is to recommend that each party have a lawyer, so both people understand their rights and obligations before they sign.
Milestones & recognition
- 2003: Sean Plat began offering collaborative family law services, and holds Level I and Level II collaborative practice certificates.
- Sean Plat has been recognized in Best Lawyers since 2024.
In the community
- Plat Simionati publishes educational articles on Ontario family law, covering subjects like exclusive possession of the matrimonial home, the "first families first" rule for support when a payor has a second family, Keira's Law (Bill C-233), and the Supreme Court of Canada's 2023 ruling in Anderson v. Anderson.
Lawyers
No individual lawyers listed on the firm site.
The neighbourhood
Plat Simionati works out of 258 Woolwich Street, a two-storey limestone house built in 1871-72 for Samuel Hodgskin, an accountant, who's believed to have added the brick wing at the back around 1877. The City of Guelph protected it under a 1983 heritage designation bylaw. After being divided into four apartments in the late 1940s, the house was extensively restored in early 1981. It's one of three stone houses in differing styles that make up a unified group between Charles Street and Edwin Street.
Woolwich Street is also home to the Wellington County Jail and Governor's Residence at number 74, both built in 1911. That property now houses an Ontario Court of Justice.
Frequently asked questions
- Can Sean Plat of Plat Simionati be the mediator for both of us, rather than one side's lawyer?
- Plat Simionati's Sean Plat is a trained mediator who can act as mediator for separating parties, on top of representing clients in mediation. Sean Plat completed a Certificate in Family Mediation through Riverdale Mediation Training and Consulting in 2022.
- My spouse and I own a business together. Can Plat Simionati help sort out its value when we separate?
- Plat Simionati has built up a network of valuators, accountants and tax advisors over its years in practice, and they can help with a business's fair value and with the tax effects of different settlement options.
- Will Plat Simionati help me keep our dog after the separation?
- Plat Simionati's family lawyers help clients deal with pet custody and protect their relationship with the animal, whether it was bought or adopted.
- Does Plat Simionati's Sean Plat work with unmarried couples and LGBTQ+ clients?
- Plat Simionati's Sean Plat works with married and unmarried spouses alike and with the LGBTQ+ community.
Where to find them
258 Woolwich Street Guelph, Ontario N1H 3W1 · 519-780-4638
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Legal AidThis listing was generated by AI from public sources in October 2026. It may contain errors, and we can’t guarantee it’s accurate or complete. Before you rely on anything here, verify it on the firm’s own website. Verify licence status in the Law Society of Ontario directory ↗
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