Can someone be declared a vexatious litigant in Ontario family court after repeated meritless filings?

Yes. Where a party has a documented pattern of bringing repeated proceedings, motions, or appeals that are without merit, and the pattern shows the court process is being used to harass, intimidate, or wear down another party rather than to resolve a genuine dispute, a court can restrict that person's ability to start further proceedings or bring further motions without first getting the court's permission. This is a significant step, generally reserved for clear, serious patterns rather than a single unsuccessful motion or an ordinary contested case.

Getting this kind of restriction in place typically requires bringing it to the court's attention directly, with a clear history of the specific filings, their outcomes, and why they show a pattern of misuse rather than legitimate, if unsuccessful, advocacy. Once in place, the restriction doesn't prevent the person from ever going to court again — it means they need to seek the court's leave first, which lets a judge screen out further meritless filings while still preserving access to justice for any genuine issue. Anyone facing this kind of pattern from the other side should keep organized records of every filing and its outcome, since that history is what supports the request.