In law, paternity is the legal acknowledgment of the parental relationship between a man and a child usually based on several factors.

At common law, a child born to the wife during a marriage is the husband's child under the "presumption of legitimacy", and the husband is assigned complete rights, duties and obligations as to the child. The presumption, however, can be rebutted by evidence to the contrary, at least prior to a formal court ruling involving the putative paternity (often this is a decree of divorce, annulment, or legal separation). Jurisdictions differ widely on when a judgment establishing paternity or a support obligation based on the presumption can be set aside on the grounds that the husband was not in fact the father.

In the case of an unwed mother, a man may come forward and accept the paternity of the child, the mother may petition the court for a determination, or paternity can be determined by estoppel over time.

Where paternity of the child is in question, a party may ask the court to determine paternity of one or several possible fathers (called putative fathers) based initially upon sworn statements and then upon testimony or other evidence.

Paternity may refer to:

The Law is a system of rules and guidelines which are enforced through social institutions to govern behavior. Laws are made by governments, specifically by their legislatures. The formation of laws themselves may be influenced by a constitution (written or unwritten) and the rights encoded therein. The law shapes politics, economics and society in countless ways and serves as a social mediator of relations between people.

A general distinction can be made between civil law jurisdictions (including Canon and Socialist law), in which the legislature or other central body codifies and consolidates their laws and common law systems (including Sharia), where judge-made binding precedents are accepted. In some countries, religion may inform the law; for example, in jurisdictions that practice Islamic law, Jewish law or Canon law.

The adjudication of the law is generally divided into two main areas. Criminal law deals with conduct that is designated dishonest by the government and in which the guilty party may be imprisioned or fined. Civil law (not to be confused with civil law jurisdictions above) deals with disputes between individuals or organizations, in which compensation may be awarded to the wronged litigant.