Polly is an old English pet form of Mary, reached by way of Molly, and so shares its meaning, usually given as "beloved" or "bitter", from the Hebrew Miriam. The nursery rhyme Polly Put the Kettle On and the heroine of the 1913 novel Pollyanna made it a cheerful classic. Polly is rare in the United States but inching up: from number 3244 in 2015 to number 2318 in 2025.