Is a parking spot or gym membership my Ontario employer gives me a taxable benefit?

Generally, yes, for both — though for slightly different reasons. Employer-provided parking is usually treated as a taxable benefit added to your income, unless it's genuinely tied to a specific business need, such as a job that requires you to use a vehicle for work, or a scarce parking allocation given for a documented business reason rather than as a general perk.

A gym membership paid directly by your employer is generally treated as a taxable benefit as well. This surprises people because it feels like a health-related perk rather than compensation, but the general rule under the Income Tax Act is that almost any benefit an employer provides because of your employment is presumptively taxable unless a specific exception applies, and a straight gym membership doesn't fall into one of the recognized exceptions.

Both of these are genuinely fact-dependent at the edges — the "business need" exception for parking and the way a wellness benefit is structured can change the analysis — so it's worth looking closely at how a specific perk is set up rather than assuming a general label like "parking" or "wellness" automatically settles the tax question. If your employer treats either as taxable, it should show up as an added amount in your income with the usual withholding.