Ettrick Bay is a wide, tidal, sandy coastal embayment with a chord of 1 mile (2 km), on a 218° bearing, located on the west coast of the Isle of Bute in the Firth of Clyde, within council area of Argyll and Bute in Scotland.

[1] The bay is bounded by a coarse sandy beach which is popular with tourists and local people.

The small coastal village of Port Bannatyne is located 2 miles (3 km) to the north east, on Ardbeg point of Kames Bay.

A Bronze Age stone circle is situated at St Colmac Farm, which is located south of the B875 road to Ettrick Bay from Port Bannatyne, about 0.6 miles (1 km) northeast of the shore of Ettrick Bay.

At the bridge over Glenmore Burn lie concrete frames built for the British Army for exercises on Inchmarnock.