A marriage license is a document issued, either by a church or state authority, authorizing a couple to marry. The procedure for obtaining a license varies between countries and has changed over time. Marriage licenses began to be issued in the Middle Ages, to permit a marriage which would otherwise be illegal (for instance, if the necessary period of notice for the marriage had not been given).

Today, they are a legal requirement in some jurisdictions and may also serve as the record of the marriage itself, if signed by the couple and witnessed.

In other jurisdictions, a license is not required. In some jurisdictions, a "pardon" can be obtained for marrying without a license, and in some jurisdictions, common-law marriages and marriage by cohabitation and representation are also recognized. These do not require a marriage license. There are also some jurisdictions where marriage licenses do not exist at all and a marriage certificate is given to the couple after the marriage ceremony had taken place.