The Round Church stands in a magnificent location at the head of the village of Bowmore's Main Street. From here it dominates the village and offers views down the centre of Main Street to Loch Indaal and beyond. It has been described as Islay's best known building, and, give or take a few distilleries, that is very probably true.
The Round Church is the commonly used name for what is formally know as Kilarrow Parish Church. It was built between 1767 and 1769 by Daniel Campbell of Shawfield and Islay, who at the time owned Islay in its entirety. The following year work began on a planned village which greatly expanded the existing settlement of Bowmore. Campbell's development of Bowmore was not driven solely by altruistic motives. The new settlement was intended to generate increased rental income, and to allow the clearance of the area's main settlement of Kilarrow, near Bridgend. This in turn was intended to remove development from the area around Campbell's hereditary home, Islay House, and allow its gardens and grounds to be extended. A cynic might suggest that the development of the church was intended to help gain the acceptance of those being moved from Kilarrow to new planned village at Bowmore.
https://www.undiscoveredscotland.co.uk/islay/roundchurch/index.html