Saanich Inlet, Saltwater inlet in British Columbia, Canada

Saanich Inlet is a 25 km saltwater inlet between the Saanich Peninsula and the Malahat highlands of Vancouver Island, northwest of Victoria. It runs from Satellite Channel to Squally Reach and Finlayson Arm, covers 67 km2 and reaches 226 m deep. The Goldstream River is its only major tributary.

People have lived on the inlet's shores since about 2000 BCE: the Malahat on the west side and the Tseycum, Tsartlip, Tsawout and Pauquachin on the Saanich Peninsula. The inlet was carved during the Ice Age about 11,000 years ago, and glacial debris left a shallow sill at its mouth. European immigrants arrived in the 19th century.

The inlet's shores are home to the Malahat First Nation on the west side and the Tseycum, Tsartlip, Tsawout and Pauquachin on the Saanich Peninsula. These five communities have fished its waters for centuries, and several reserves sit directly on the shoreline.

The inlet runs 25 km from Satellite Channel to Squally Reach and Finlayson Arm, with Brentwood Bay on the east side and Mill Bay on the west; a small ferry links the two, avoiding the steep Malahat Drive. Deep water is anoxic for most of the year, with hydrogen sulphide near the bottom, so diving is best in late summer and early autumn when oxygenated water from Haro Strait and Satellite Channel spills into the basin.

For most of the year the deep basin is anoxic, and hydrogen sulphide is often detected near the bottom. In late summer and early fall, oxygenated water from Haro Strait and Satellite Channel spills over into the deep basin, so the inlet's lower layers renew only once a year.