Who pays the legal costs of a dependant support claim if it's unsuccessful in Ontario?

There's no fixed rule. In Ontario civil and estate litigation, costs generally follow the outcome, meaning an unsuccessful claimant can be ordered to pay some of the other side's legal costs — but courts have broad discretion and weigh more than just who won. In estate litigation specifically, courts sometimes take a more flexible approach than in ordinary civil disputes, particularly where a claim was reasonably brought and raised genuine questions about the deceased's obligations, though that's not a guarantee an unsuccessful dependant will avoid a costs award.

Conduct during the case matters too — how reasonably each side behaved, whether settlement offers were made and rejected, and how the claim was argued can all affect the final costs decision. Because outcomes vary significantly case to case, no one should assume in advance that an unsuccessful claim will be cost-free, or that it will automatically trigger a large costs award either. Anyone considering a dependant support claim should ask the lawyer handling it about realistic costs exposure before proceeding, since this is one of the more case-specific parts of estate litigation.