He was born in Palermo where his father, Sir John Acton, 6th Baronet, a former Prime Minister of Naples, had been forced to flee in 1806.
On 23 January 1837 Sir Richard and his friend Lord Augustus Loftus attended a party at the Tuileries Palace.
Thereafter Sir Richard's fever worsened; he was dosed with nux vomica (strychnine) and aconite (wolf's bane) and died at 2am on 30 January 1837.
By 11am 600 mourners had gathered outside the house where he died and "When the funeral procession left the Hotel de Mortemart to proceed to the church of St. Thomas, all the company followed on foot the funeral car, immediately after which walked - first, the family of the deceased, then the Ambassadors of Russia, Austria, and Prussia, and most of the members of the corps diplomatique.
The King, who with the rest of his family had always honoured the Chevalier Acton with the most marked attention, sent one of his aides-de-camp to represent him at this mournful ceremony.