Earlier this month the controversial professor Jordan Peterson of the University of Toronto became the plaintiff in a slander suit against a professor at Wilfred Laurier University. If this were in the United States, I suspect Peterson's status as a "public figure" might make it difficult or impossible for the plaintiff to prevail. What, if anything, would be the effect of that status on this lawsuit?
I don't believe Canada uses the public official/figure distinction. American defamation law uses the distinction to determine whether to require proof of actual malice, but Canada does not require proof of actual malice.
Canadian defamation law has a lot of other parallels to American defamation law, though, especially in terms of privilege. I'd expect the University could claim any of several available privileges, including truth, qualified privilege, and fair comment. And because it's a government institution, it's conceivable that it might even claim absolute privilege, though I definitely don't know enough about their interpretations of the privilege to say one way or another.
For a broad primer on defamation law in Ontario, you can check out this report from the Law Commission of Ontario.
The "Actual Malice" requirement for defamation cases against US public officials, later extended to apply to public figures who are not officials, was created by the US Supreme Court in New York Times Co. v. Sullivan, 376 U.S. 254 (1964). The requirement was a way of applying the protections of the US First Amendment (via the 14th) to defamation law. My understanding is that there is nothing similar in Canadian law
The term "actual malice" was current in defamation law before the Sullivan case. In some jurisdictions (I don't know about Canada) one must prove actual malice in order to be awarded punitive damages. The Sullivan court borrowed th term, and the concept, for a significantly different use.
Thew Wikipedia article Canadian Defamation Law says:
Broadly, Canadians can be held liable by English-Canadian courts for comments on public affairs, about public figures, which are factually true, and which are broadly believed. They cannot be held liable for opinion, inference, hyperlinking without explicit agreement with the content, reportage when this is based on honest research and journalistic ethics. Plaintiffs need not prove falsity, malice or damages. Politicians can, and do, sue including during elections for political advantage or to silence critics or accusers. Evidence can be gathered by spies representing themselves falsely in private conversations. Defendants, once accused, are prima facie liable until they prove themselves innocent (reverse onus). Anonymous persons can be exposed for political comment, even if they are vulnerable and reside in jurisdictions where retribution is likely. People may be sued from remote jurisdictions if publication can be proven in that remote jurisdiction, which can mean as few as one person seeing the words. By contrast, under English law, a substantial publication is required before a plaintiff can sue a defendant in an English court. (citations and "citation needed" tags omitted)