Mill Bay is a commuter town of about 7,200 people located on Vancouver Island, British Columbia, Canada, about 30 km (19 mi) north of Victoria, the capital.

It was named for the sawmill built in the area in 1861 by Henry S. Shepherd soon purchased by William Sayward.

[1]: 174  It is known for its ferry to Brentwood Bay on the Saanich Peninsula and the historic Malahat Drive, which is also a source of criticism due to frequent closures from either automobile accidents or weather conditions.

Brentwood College is a private high school located in Mill Bay.

The Mill Bay Freemasons Hall meets on the third Thursday of the month and also offers room to other community organizations.