Molly \m(ol)-ly\ as a girl's name is pronounced MAH-lee. It is of Irish origin. Ppet form of Mary (Latin) "star of the sea". In use since the late Middle Ages. In the past, "moll" had meant a prostitue or a gangster's girlfriend, making the use of this name uncommon. Now revived in popular usage, also possibly due to actress Molly Ringwald. Author Mollie Hardwick.
For more information, see also the related name Polly.