Common law marriage—also known as marriage without formalities or informal marriage—is marriage without a wedding or marriage ceremony and without a marriage license. Some states recognize common law marriage under certain circumstances—such as when the parties agree to be married, live together (cohabit) after agreeing to be married, and represent to others that they are married (holding themselves out as a married couple).

Other states previously recognized common law marriages, but no longer recognize such marriages after a certain date on which the law was changed—usually by statute. In other states, common law marriage has not been recognized by the legislature in a statute, but the courts have recognized common law marriage in court opinions or case law.

New Jersey does not recognize common law marriage as a means for couples to become legally married, regardless of how long a couple has lived together or whether they hold themselves out as a married couple. The state abolished common law marriage in 1939, and since then, the only way to legally establish a marriage in New Jersey is through a formal process that includes obtaining a marriage license and having a marriage ceremony. However, New Jersey does recognize common law marriages that were established in other states where it is legally recognized, provided that the marriage meets the requirements of the state where it was established. This recognition is due to the Full Faith and Credit Clause of the U.S. Constitution, which requires states to respect the 'public acts, records, and judicial proceedings' of every other state.