Is there an oppression remedy for members of an Ontario not-for-profit corporation, like for shareholders?

Yes. ONCA gives members (and certain other people with a real stake in the corporation, similar to the "complainant" concept under business corporation law) access to an oppression remedy, modelled closely on the one long available to shareholders under the Business Corporations Act. A court can grant relief where the corporation's conduct, or its directors' conduct, is oppressive, unfairly prejudicial to, or unfairly disregards the interests of a member.

This matters because volunteer boards sometimes assume that, since not-for-profit members don't have a financial investment at stake the way shareholders do, members have little real recourse if a board sidelines them, ignores the by-laws, or makes decisions in a way that disregards their legitimate interests. The oppression remedy is exactly the tool that pushes back against that assumption — courts can order a range of remedies, from requiring the corporation to do (or stop doing) something, to more significant structural relief.

Because oppression claims are fact-heavy and the remedy is broad but not automatic, a member considering this route, or a board facing a threatened claim, should get advice early on the specific conduct at issue rather than assuming either that the remedy is unavailable or that it is easily won.