He was the eldest son of Robert Byng (1703-1740), Governor of Barbados, by his wife Elizabeth Forward, a daughter and co-heiress of Jonathan Forward. He was a grandson of Admiral George Byng, 1st Viscount Torrington (1663-1733) of Southill Park in Bedfordshire.
He inherited the estate of Wrotham Park from his unmarried and childless uncle Admiral John Byng (1704-1757), famously court-martialled and shot in 1757 following the fall of Minorca. At the 1768 general election Byng was elected as a Member of Parliament for Wigan. He was returned unopposed for Wigan in 1774. He was returned unopposed as MP for Middlesex at the 1780 general election but was defeated in a contest in 1784.
On 5 March 1761 Byng married Anne Conolly (died 1806), daughter of William James Conolly (d.1754) by his wife Lady Anne Wentworth, a daughter of Thomas Wentworth, 1st Earl of Strafford (1672-1739). William James Conolly was an Irish Member of Parliament and was the nephew and heir of William Conolly (1662-1729), of Castletown House, County Kildare, Speaker of the Irish House of Commons, reputed to be the wealthiest man in Ireland. By his wife he had progeny including:
He died on 27 October 1789.
|Parliament of Great Britain|
| Member of Parliament for Wigan
With: Beaumont Hotham 1768-1775
John Morton 1775-1780
Henry Simpson Bridgeman 1780
Hon. Horatio Walpole
Henry Simpson Bridgeman
| Member of Parliament for Middlesex
With: John Wilkes