Sir Jacob Garrard Downing, 4th Baronet was an English baronet and politician. He was the grandson of Sir George Downing, 1st Baronet, namesake of Downing Street; and cousin and heir of Sir George Downing, 3rd Baronet, whose Gamlingay estate would eventually establish Downing College, Cambridge despite illegal attempts by Jacob and his widow to prevent the university from receiving the estate.

Sir George Downing, 3rd Baronet was a British landowner and initially Tory, but later Whig politician who sat in the House of Commons between 1710 and 1749. Through a donation in his will, he was the founder of Downing College, Cambridge.