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.

In Louisiana, common law marriages are not recognized. Louisiana law requires that a marriage be contracted by a ceremony performed by an authorized person and that the parties obtain a marriage license. Additionally, the marriage must be recorded in the official registry. The state does not provide legal recognition to relationships that would be considered common law marriages in other states, regardless of the length of the cohabitation or the parties' representation of themselves as married. This means that couples who cohabit without a formal marriage in Louisiana do not acquire the legal rights and responsibilities that are associated with legal marriage. It is important for individuals in such relationships to be aware that they do not have the same legal protections as married couples, particularly in matters of property, inheritance, and other legal benefits.