Kit-Cat Club, a society formed in London about 1700, consisting of thirty-nine noblemen and gentlemen favourable to the succession of the House of Hanover, and whose ostensible object was the encouragement of literature and the fine arts. Jacob Tonson, an eminent publisher, was founder and secretary; and, not to mention dukes and earls, it included Sir Robert Walpole, Vanbrugh, Congreve, Addison, Steele, and Garth. The club derived its name from having met for some time in the house of Christopher Catt, a pastrycook.
Before its dissolution (about 1720) each of the members gave Tonson his half-length portrait, painted a uniform size, by Kneller. Hence a kit-cat is any portrait of that size—about 36 in. by 28.