He was the son of William Richardson (1710–1758) of Rich Hill, County Armagh, Ireland and succeeded him to the Richhill estate when only a minor.
[1] He was the great-nephew of another William Richardson, who was Member of Parliament for County Armagh at the time of the Williamite War in Ireland.
In 1807 he was elected to sit for County Armagh in the House of Commons of the United Kingdom, serving until 1820.
She was a noted beauty who while staying in Dublin with her aunt Frances, Lady Loftus, had been courted by Henry Grattan, Sir Hercules Langrishe, Francis Andrews, Provost of Trinity College, and the recently widowed Viceroy Lord Townshend.
Only the youngest daughter married (to Edward Bacon, sometime High Sheriff of Armagh), and when she died without heirs in 1881 the estate passed to the Richardsons of Rossfad, near Ballinamallard in County Fermanagh.