The Kilbrannan Sound outdated, even Kilbrandon, is the western arm of the estuary Firth of Clyde in Scotland. The name is derived from the Irish Saint Brendan, who traveled the western islands in 545.
The waterway runs essentially north-south direction and separates the Isle of Arran from the east of the Kintyre peninsula. It has a length of 32 km and a maximum width of 13 km. In the north of Kilbrannan Sound runs out into the sea lochs of Loch Fyne and the Kyles of Bute, in the south it branches off from the Firth of Clyde. Campbeltown Loch in the south is the largest bay of the Kilbrannan Sound.