Jane Doe is a fictitious name for a female party to a legal proceeding. Such a name is used because the party's true identity is unknown or because her real name is being withheld. Jane Doe is also referred to as Jane Roe and Mary Major.
The landmark United States Supreme Court abortion case Roe v. Wade, 410 U.S. 113 (U.S. 1973) gets half of its name from Jane Roe, an anonymous plaintiff later revealed to be Norma McCorvey.
The male equivalent of Jane is John Doe.