Are you required to report audited courses when applying for graduate school? I recently noticed that a few of the courses I am required to take for my undergraduate program are also offered by an online university, and that they allow you to audit said courses relatively cheaply. Would it be a good idea to study ahead using these courses, or is such a thing considered unethical as it would give me an advantage when I take the course at my own institution? Am I generally required to report the audited courses when I later apply for graduate school (which would presumably look 'bad')?

Specifically I am in Canada if the rules vary by region.
Don't worry about it.

I don't believe I've ever heard of a school requiring that audited courses must be reported when applying for admission. Essentially, if you're not getting some sort of official recognition for having taken the course (credit or placement in some form), then you don't have to report it.

As far as "getting an (unfair) advantage" from it, you could get a similar advantage by getting the textbooks for your courses over the summer and reading them ahead of time. Nobody would expect you to report that or call it unethical, so why would it be any different just because you audited an online course?