It depends on the park. There are seven provincial parks that ban dogs outright to protect sensitive ecosystems: Bowron Lake, Bugaboo, Cathedral, Garibaldi, Joffre Lakes, Kokanee Glacier, and Monashee.
Most of BC’s provincial parks allow dogs in the park as long as they’re on a leash at all times. Dogs aren’t allowed inside park buildings or on public beaches. Some parks have additional no-go areas that are marked by signs or under the “Pets on Leash” symbol on the park’s website.
These requirements are under BC’s Park, Conservancy and Recreation Area Regulation.
Several provincial parks have off-leash areas and dog-friendly swimming areas — a list of these is available on the BC Parks website.
If you’re not sure, you can also check the website of the specific park you’re going to. Look for the “Pets on Leash” symbol under “Activities Available at this Park” for more details on the rules of that park.