What rights does a minority shareholder actually have if they weren't consulted about a sale?

Minority shareholders generally have statutory rights to proper notice of shareholder meetings, to receive relevant financial information, and to vote on matters — like a sale of all or substantially all of a corporation's assets — that require shareholder approval by special resolution, so being deliberately excluded from that process can be a serious problem rather than a minor oversight.

Beyond these formal rights, Ontario's oppression remedy under the Business Corporations Act allows a court to grant relief where a corporation's affairs have been conducted in a way that unfairly disregards a shareholder's interests, which can include being frozen out of a major decision like a sale. What relief looks like varies with the circumstances — it can include an order affecting the transaction, compensation, or other remedies a court considers appropriate. A minority shareholder who discovers they were excluded from a sale process should get legal advice promptly, since acting quickly matters both for showing the exclusion was serious and for preserving realistic options.