No-fault divorce is the dissolution of a marriage that does not require a showing of wrongdoing by either party. Laws providing for no-fault divorce allow a family court to grant a divorce in response to a petition by either party of the marriage without requiring the petitioner to provide evidence that the defendant has committed a breach of the marital contract.

In early modern Europe, Prussia took a pioneering role with Frederick the Great's 1757 edict allowing marriages to be dissolved on the ground of serious and continuous hostility between spouses, without pointing to any one guilty party. This early example of no-fault divorce was expanded on and formalized with the 1794 General State Laws for the Prussian States, which allowed childless couples to file for divorce without giving a ground.

The first modern no-fault divorce law was enacted in Russia in December 1917 following the October Revolution of the same year. Regarding marriage as a bourgeois institution, the new government transferred divorce jurisdiction from the Russian Orthodox Church to the state courts, which could grant it on application of either spouse. Alimony guarantees under the new regime were weak until a new family code was passed in 1926.

With a law adopted in 1969, California became the first U.S. state to permit no-fault divorce. California's law was framed on a roughly contemporaneous effort of the non-governmental organization National Conference of Commissioners on Uniform State Laws, which began drafting a model of no-fault divorce statute for states to consider in 1967.

The Uniform Marriage and Divorce Act (UMDA) is a model law in the United States and has been used since 1970.

Australia established no-fault divorce in 1975, with the only ground for divorce being irretrievable breakdown of marriage, evidenced by a twelve-month separation. Canada effectively permitted no-fault divorce in 1986 by reducing the separation period to one year.

Several studies have looked at the effect of no-fault divorce on divorce rates in the United States. The studies typically find an increase in the short-term rate but little long-term causal relationship. The most frequent explanation given is that the older laws were ineffective and not followed anyway, though there are some differing viewpoints. Economists Betsey Stevenson and Justin Wolfers, based on findings in their research, argue that domestic violence and female suicide declines in states that legalize no-fault divorce. Specifically, they report that "states that adopted no-fault divorce experienced a decrease of 8 to 16 percent in wives' suicide rates and a 30 percent decline in domestic violence." They also argue that their research proves that there is no permanent effect of no-fault divorce laws on divorce rates.

Stephanie Coontz, a professor of history at Evergreen State College, states that "in the years since no-fault divorce became well-nigh universal, the national divorce rate has fallen, from about 23 divorces per 1,000 married couples in 1979 to under 17 per 1,000 in 2005." She adds that "once you permit the courts to determine when a person's desire to leave is legitimate, you open the way to arbitrary decisions about what is or should be tolerable in a relationship, made by people who have no stake in the actual lives being lived."