Can the outcome of a proof in solemn form hearing be appealed in Ontario?

Yes. A decision reached after a proof in solemn form hearing — essentially a trial on the will's validity — is a final decision on the merits and can generally be appealed like any other trial outcome in Ontario civil litigation, whether the will was found valid or invalid. Because proof in solemn form typically involves live witnesses, expert or medical evidence, and detailed factual findings by the judge, an appeal usually focuses on whether the judge made a legal error or a clear, significant error in assessing the evidence, rather than simply re-arguing the same facts to a new decision-maker.

Appeal courts generally give real deference to a trial judge's findings of fact and their assessment of witness credibility, since the trial judge saw and heard the evidence directly. This means an appeal following a solemn form hearing tends to succeed only where there's a genuine legal error, not simply because the losing side would have preferred a different result on the same evidence. As with other estate litigation decisions, strict and often short deadlines apply to filing an appeal, and the right appeal court depends on the specific order being appealed, so get legal advice immediately if you're considering challenging the outcome.