Thomas Hamilton was the son of Charles Hamilton, Lord Binning and Rachel Baillie of Mellerstain and Jerviswood. Lord Binning had predeceased his father Thomas Hamilton, 6th Earl of Haddington in 1732, and from then until 1735 when his grandfather died Hamilton was known as Lord Binning, and thereafter as Lord Haddington.
Haddington was educated at Oxford University, and travelled widely on the continent, residing at Rome and later Geneva, where he became part of what was known as the "Common room" involving Benjamin Stillingfleet amongst others
Haddington returned to Scotland by 1744 but did not greatly participate in public life. He died at Ham, London on 19 May 1794.
