Plumper Sound is a sound in the Southern Gulf Islands region of British Columbia, Canada, located between Saturna Island (E) and North and South Pender Islands. It is named for , the survey ship of the Royal Navy engaged in charting the coastal waters of British Columbia in the colonial period.
Plumper Sound should not be confused with Plumper Cove, a small cove that is home to the Plumper Cove Marine Provincial Park on Keats Island, also named after HMS Plumper.