The iconic British Prime Minister during the Second World War, Winston Churchill — a scion of the great Marlborough aristocratic dynasty — has occasionally been claimed to have been jewish. The basis of this claim is the assertion that his New York–born American mother, Jennie Jerome, was a jewess who had come to America from the Russian Empire.
In reality, however, Jenny Jerome was born to Leonard and Clara Jerome in Pompey Hill in Syracuse, New York. (1) Both sides of the family were a mix of Huguenot and Scottish stock (2) with the line being dated back to one Timothy Jerome, a Huguenot refugee who left France in 1710 for the Isle of Wight and then sailed for Connecticut. (3)
Now, despite the fact that Jennie’s father Leonard Jerome was a playboy who had numerous mistresses and illegitimate children with his wife’s knowledge (4), there is no serious suggestion in the biographical literature that Jennie Jerome was jewish, because we know her ancestry back to the 1700s, and there is nothing jewish about it.
That said, there is a Jerome family myth — which Winston Churchill himself believed to be true — that the family is partly descended from the Iroquois Indians, (5) but this is disbelieved by biographers as well.
So, no, Winston Churchill was not jewish.
(1) Elisabeth Kehoe, 2004, ‘Fortune’s Daughters: The Extravagant Lives of the Jerome Sisters: Jennie Churchill, Clara Frewen and Leonie Leslie’, 1st Edition, Atlantic: London, p. 2
(2) Ibid.; Anna Sebba, 2007, ‘ Jennie Churchill: Winston’s American Mother’, 1st Edition, John Murray: London, pp. 1-2
(4) William Manchester, 1983, ‘The Last Lion: Winston Spencer Churchill’, Vol. I, 1st Edition, Little, Brown and Company: Boston, p. 99
(5) Sebba, Op. Cit., p. 4