Molly started out as a pet form of Mary, which has been used since the 18th century. It is an alteration of an earlier pet form, Mally, which fell out of use when Molly took over. People associate this name with Ireland, but it was used in England just as much (see the book Moll Flanders by Daniel Dafoe, 1722). When the Normans invaded England in 1066, they brought new sounds to the language that were difficult for the native populations to pronounce. The "r" and "l" sounds were among the confused. Thus, many diminutive forms of names either dropped their "r" sounds (as Frances became Fanny, and Brigid became Biddy) or else changed it. This is how Mary became Moll and Molly (also Sarah became Sally, Henry became Hal etc.)

An interesting factoid: in a study done for their book Freakonomics, by Steven D. Levitt and Stephen J. Dubner found that Molly is the number one "whitest" name (i.e., one given to the most number of white people and not used by other races) in the U.S.A.
See Also: Mary, Polly

Your Favorite Names