Coordinates: 55°45′04″N 5°01′26″W / 55.751°N 5.024°W
Kilchattan Bay is village on the Isle of Bute, Scotland. It lies the island's southern end, along the coast road at the foot of a steep hill called the Suidhe Chattan which shields the village from the prevailing westerly wind. The village faces the mainland to the east across the Firth of Clyde. A sandy bay known locally as the Wee Bay sweeps around to the north.
To the south along the coast is the start of the West Island Way which leads along the rocky shore and past the lighthouse which marks the southern end of the island.
The village is named after the sixth century bishop, Saint Cathan, who established a hermitage at this location in AD 539. His nephew was Saint Blane and a chapel was established in his honour in the 12th century. St. Blane's Chapel still exists as a ruin, one mile to the south of Kilchattan village.
The village developed as a row of fisherman's houses. Further developments included a quarry, stone pier and a lime kiln which can still be seen behind St. Blane's Villa. The limestone used in the kiln being mined on the hillside behind the village. Part of the old mine workings is now used as the reservoir for the village. Overlooking the reservoir is the ruined remain of Kelspoke Castle.