Grenville Channel is a strait on the North Coast of British Columbia, Canada, between Pitt Island and the mainland to the south of Prince Rupert. It is part of the Inside Passage shipping route, about 45 nmi long and is 0.2 nmi wide at its narrowest point. The Grenville Channel Fault that forms the channel dates back to the Cretaceous Era. Both sides are mountainous and densely wooded, and a linear magnetic anomaly runs parallel to the channel south of 51"30'N.