Adamwas the most famous of the four sons of the Scottish architect William Adam (1698–1748).
He was brought up in Edinburgh and went to university there (1743–1745). His family circle was that of the Edinburgh Enlightenment, and he was related to the Scottish historian William Robertson and a close friend of David Hume. Though a proud Scot as well as a Scottish member of Parliament for Kinross-shire, he was essentially a man of northern Britain and, as such, part of the mainstream of European thought. His departure for Italy in 1754 was an expression of this intellectual attitude.