[1] He was educated at Westminster School in 1748 and Trinity College, Oxford, matriculating in 1757, before succeeding his uncle in 1757 as fifth Earl of Donegall.

[2] After taking his seat in the Irish House of Lords in 1765, Donegall served at Westminster as Member of Parliament for Malmesbury (1768–1774) by his friend Lord Suffolk, first following Suffolk and the Grenville group.

The following year he was also created Earl of Belfast and Marquess of Donegall in the Peerage of Ireland.

[6] Lord Donegall held on lease a country residence at Butley Priory, Suffolk.

He died on 5 January 1799, aged 59, at his London home in St James's Square, Westminster.