By Vanessa Lam, Strategic Advisor and Research Lawyer, Lam Family Law*

Last week, Maria Golarz and I had the opportunity to participate in the National Family Law Program in beautiful Kelowna, BC. We both appreciated the valuable opportunity to meet and learn from colleagues from across Canada.

We were also honoured to present our paper, Mischief Managed: Dealing with Vexatious Litigation in Family Law, which covers:

  • vexatious litigant and vexatious proceeding orders (including the applicable legislation and case law from each province and territory in Canada),
  • the related concepts of abuse of process by relitigation, res judicata, and litigation abuse, and
  • a brief discussion of alternative remedies (e.g., striking out parts of a document or claim, increased costs, etc.).

However, the law always evolves. Here are a few key Ontario cases that I mentioned in our presentation that were not included in our paper. I thought this blog post could act as a short follow up to the paper.

Vexatious Litigants in Ontario

Kim v. McIntosh, 2026 ONSC 3215 (CanLII), was released on June 2, 2026 (after the paper was submitted, and thanks to Ken Younie for bringing this case to my attention). This case is an example where the judge, Justice Sah, initiated the hearing to declare the father a vexatious litigant of her own initiative. She did this by serving and filing her “Endorsement/Written Direction to Registrar Pursuant to Rule 2.2.04(1)” and a special Rules of Civil Procedure Form, “Form 2.2C – Registrar’s Notice Proposing Consideration of Vexatious Litigant Order”: at para 3. Note that both parties were, at this point, self-represented.

I highly recommend this case because the court made a very detailed vexatious litigant order, which included ordering the vexatious litigant to deliver a copy of its order to any person or body against whom the vexatious litigant institutes or continues any proceeding in any court, administrative body, and/or tribunal regulatory body, the police, and the Crown: see para 161(2)(c).

Her Honour also very helpfully sets out the exact method by which the father may seek leave in the future, which for a family matter, is to be by a simplified Form 14B motion form with an affidavit to Justice Sah herself, or her designate. Any such motion will be heard presumptively in writing, and specific information must be attached and included in the affidavit. The judge considering the motion for leave may, but shall not be required to, give notice to the proposed respondents, who would be given the chance to respond, if they so choose: see para 161(2)(e).

Ahluwalia and Litigation Abuse in Ontario

When writing the paper, we found less Ontario family law cases than expected on the issue of litigation abuse (or at least using that terminology), especially when compared to other jurisdictions (e.g., BC) and given the richer body of case law on vexatious litigants in Ontario.

However, with the landmark decision of Ahluwalia v. Ahluwalia, 2026 SCC 16 (CanLII) (released in May 2026), we expect that to change. Amongst the many things covered in that decision (reviewed in more detail in my earlier blog, The Newest Addition to the Family: The Tort of Intimate Partner Violence), the Supreme Court of Canada recognized the concept of litigation abuse and how it can be a form of coercive control. We expect lower courts will continue to pick up on this definition of litigation abuse in the context of considering damages for tortious behaviour, and in other contexts as well.

One example is D.M.S. v. E.L.R., 2026 ONSC 3726 (CanLII), which was released on June 25, 2026 (and thanks to Shmuel Stern’s corollary relief X feed for bringing this case to my attention). Here, the court was concerned with the issue of weaponizing civil proceedings to attack the defendants in the context of prior family law proceedings. Justice McDermot quoted from Ahluwalia, where the majority noted that abusers frequently use litigation to abuse their ex-partners: at para 14, citing from Ahluwalia, at para 194. For a further discussion of “the weaponization of the legal system”, see also D.M.S., at para 34.

In the current civil proceeding, D.M.S. (the father) brought a Statement of Claim naming both the mother and his now adult daughter as defendants. He claimed damages of more than $3 million for malicious prosecution, defamation, intentional interference with economic relations, and intentional infliction of mental suffering: at para 5.

On his own initiative, Justice McDermot directed that the matter come before himself for a hearing under r. 2.1.01 of the Rules of Civil Procedure, RRO 1990, Reg. 194, to determine if it was an abuse of process, frivolous, or vexatious on its face: at para 5.

Note that the parties were all self-represented on the motion. Justice McDermot had case managed the matter in Family Court and His Honour found that he had jurisdiction to address a matter in a civil proceeding, especially in light of the fact that the civil proceeding was closely related to the family proceeding, and may, in fact, be a collateral attack on the results of that family proceeding: at para 6. In the family proceeding, Justice McDermot has previously found the father to be a “querulous litigant”, which characterizes a litigant who does “not seek redress, but instead vengeance, public humiliation and punishment against those that oppose them”: para 15, citing: Olumide v. Alberta (Human Rights Commission), 2019 ABQB 186 (CanLII), at para 56.

In the result, the court found that all the claims made by the father’s Statement of Claim were frivolous and an abuse of process within the meaning of r. 2.1.01(1) of the Rules of Civil Procedure, and dismissed them in their entirety without leave to amend: at paras 51-53.

Other Definitions of Litigation Abuse in Ontario

Before the Supreme Court of Canada released Ahluwalia (which discussed, but wasn’t meant to provide one strict definition of litigation abuse), Justice Law grappled with the issue in Anyanwu v Anyanwu, 2026 ONSC 980 (CanLII), at para 67:

[67] Litigation abuse does not appear to have been defined in the caselaw yet. Professor Nicholas Bala, in his paper, “Litigation Abuse in Ontario Family Law Cases” (Paper delivered at the LSO Family Law Summit, 27 March 2025), 2025 CanLIIDocs 1843, offers a definition of litigation abuse that was cited with approval in Reeves v. Larson, 2025 ONSC 6030, at para. 60. Professor Bala defines litigation abuse as “conduct that misuses the Family Court process in a way that could reasonably be expected to cause emotional or financial harm to the other party or their children, which is greater than would occur with the proper use of the family justice process.” According to Professor Bala, “litigation abuse” describes a pattern of conduct that is abusive and causes unnecessary expense and stress to the other party. It is a form of family violence. Litigation abuse differs from “high conflict” matters as it is one-sided: Bala, at p. 2.

Her Honour found that the father’s pattern of conduct was consistent with this definition of litigation abuse. His conduct included:

  • abusive communications sent to the mother’s counsel;
  • failure to obey multiple court orders;
  • deliberate failure to comply with limits set out in practice directions and the Family Law Rules;
  • harassment of court staff;
  • repeated denigration of the mother in written documents and before the court;
  • repeated unfounded allegations against the mother;
  • repeatedly seeking review of prior orders without evidence of any change;
  • interference in the mother’s solicitor-client relationship by making unfounded allegations about her counsel; and
  • repeated, voluminous, and persistent communication with third parties about his criminal charges: at para 71.

The father’s litigation abuse – which included a consideration of his self-represented status – required a “firm judicial response”: at paras 68-69 & 72-75, citing various cases & various provisions of the Family Law Rules, O. Reg. 114/99.

Justice Law thus made “stringent case management orders to ensure that the goal of fair, timely, and proportionate justice is met”: at para 3. Her Honour assigned herself as the case management judge until trial; restricted the father’s ability to bring further motions (prohibiting motions to move back into the matrimonial home or for equal parenting time; and requiring leave for all other motions); and set out a process for court staff to reject the father’s materials if they did not comply with her directions: at paras 76 & 84(8.-14.).

Anyanwu (dated February 2, 2026; included in our paper) was also followed in A.B. v. C.D., 2026 ONSC 2583 (CanLII) (dated April 30, 2026; not included in our paper). In that case, the respondent requested DNA testing, and the applicant requested child support: paras 4-5. The court was concerned about the respondent using the family court system “to humiliate or denigrate another parent”: para 2. Associate Justice Kamal reviewed the case law on family violence and litigation abuse prior to Ahluwalia, including the cases adopting Professor Bala’s definition of litigation abuse: at paras 92-105, citing various cases.

No finding of family violence or litigation abuse was made (yet). However, Associate Justice Kamal considered these issues at this early stage “in an effort to curtail any potential efforts to use the court process to inflict emotional or financial harm on the other party or their children”: at para 106. His Honour also decided to case manage the matter and prohibited the father from speaking negatively about the mother in the presence of the children, including that the father was not to imply or discuss his concerns that the children may have been conceived through alleged sex work: at paras 107-109.

The Implications

This area of law is growing quickly, and we expect the case law to further develop more nuanced ways of dealing with vexatious litigants, coercive control, and litigation abuse. We encourage counsel and courts to take a more pro-active approach in response to litigants behaving badly, particularly in this age of delay, and of scarce client and court resources.

*with thanks to Maria Golarz for her excellent work on our paper, and her suggestions and edits on this blog post.

This blog is informational only and should not be relied on as legal advice.