Born 9 May 1774 and christened 9 June at Feltham, London he was the eldest son of the Reverend Colston Carr, at the time vicar of Feltham, and his wife Elizabeth, daughter of Thomas Bullock.[1] His elder sister, Elizabeth Ann, married James Martin Lloyd, later Sir James Lloyd, 1st Baronet and his younger brother was Lieutenant-Colonel Sir Henry William Carr, KCB. His father, later vicar of Ealing, was chaplain first to the King's younger brother Prince William Henry, Duke of Gloucester and, after his death, to the King's younger son, Prince Edward, Duke of Kent and Strathearn.