Sir George Downing, third baronet, benefactor of Downing College, Cambridge, was born at East Hatley, Cambridgeshire, to Sir George Downing and Catherine in 1685. In February 1700 Downing, aged 15, was secretly married to Mary Forester, aged 13.
Soon after the marriage Downing went abroad, and after about three years returned home yet refused either to live with or acknowledge his wife. In 1715 he supported her unsuccessful petition for divorce and two years later secured legal sanction for the couple to live separately.
Downing succeeded his father as third baronet in June 1711. Dowing created Gamlingay Park, Cambridgeshire in 1712. He was elected for the pocket borough of Dunwich, Suffolk, in the parliaments of 1710 and 1713, but lost the election of 1715. In 1722, however, he regained his seat and occupied it until his death.