War on women is a slogan in United States politics used to describe certain Republican Party policies and legislation as a wide-scale effort to restrict women's rights, especially reproductive rights. Prominent Democrats such as Nancy Pelosi and Barbara Boxer, as well as feminists, have used the phrase to criticize proponents of these laws as trying to force their social views on women through legislation. The slogan has been used to describe Republican policies in areas such as access to reproductive health services, particularly birth control and abortion services; the definition of rape for the purpose of the public funding of abortion; the prosecution of criminal violence against women; and workplace discrimination against women.

While used in other contexts, and prior to 2010, it became a common slogan in American political discourse after the 2010 congressional elections. The term is often used to describe opposition to the contraceptive mandate in Obamacare and policies to defund women's health organizations that perform abortions, such as Planned Parenthood. The concept again gained attention in the 2016 U.S. presidential election, when Republican nominee Donald Trump drew notice for a history of inflammatory statements and actions toward women.

The phrase and the concept have been criticized by Republicans and some anti-abortion Democrats. Republican National Committee chairman Reince Priebus described it as an over-simplified fiction advanced by Democrats and the media while other Republicans contended that such rhetoric was used as a distraction from President Barack Obama and the Democrats' handling of the economy. In August 2012, Todd Akin's controversial comments regarding pregnancy and rape sparked renewed media focus on the concept. Republicans have tried to turn the phrase against Democrats by using it to argue hypocrisy for not critiquing sex scandals of members within their party who have cheated, sexted, and harassed women, and for not supporting bills to combat sex-selective abortion.

Development of the term