Oncale v. Sundowner Offshore Services, 523 U.S. 75 (1998), was a landmark decision of the US Supreme Court. The case arose out of a suit for sex discrimination by a male oil-rig worker, who claimed that he was repeatedly subjected to sexual harassment by his male co-workers with the acquiescence of his employer. The Court held that the protection of Title VII of the Civil Rights Act of 1964 against workplace discrimination "because of... sex" applied to harassment in the workplace between members of the same sex.

Lesbian, gay, bisexual and transgender (LGBT) rights in the United States have evolved significantly over time, however LGBT people in the USA may face legal challenges not experienced by non-LGBT residents. Until 1962, all 50 states criminalized same-sex sexual activity, but by 2003 all remaining laws against same-sex sexual activity had been invalidated. Beginning with Massachusetts in 2004, LGBT Americans had won the right to marry in all 50 states by 2015. Additionally, in many states and municipalities, LGBT Americans are explicitly protected from discrimination in employment, housing, and access to public accommodations.

Many LGBT Americans still continue to face legal and social challenges not experienced by non-LGBT residents, particularly in states with large conservative populations, such as in the Deep South, many parts of the Midwest, in rural areas, and in some Native American tribal nations.

Many LGBT rights in the United States have been established by the United States Supreme Court. In five landmark rulings between the years 1996 and 2020, the Supreme Court invalidated a state law banning protected class recognition based upon homosexuality, struck down sodomy laws nationwide, struck down Section 3 of the Defense of Marriage Act, made same-sex marriage legal nationwide, and prohibited employment discrimination against gay and transgender employees.

LGBT-related anti-discrimination law regarding housing and private and public services varies by state, leaving residents of some states unprotected. Twenty-three states plus Washington, D.C., Guam, and Puerto Rico outlaw discrimination based on sexual orientation, and twenty-two states plus Washington, D.C. outlaw discrimination based on gender identity or expression. The Equality Act, which is currently proposed in the United States Congress, would outlaw discrimination based on sexual orientation and gender identity nationwide.Family law also varies by state. Adoption of children by same-sex married couples is legal nationwide since June 2015 following the Supreme Court's decision in Obergefell v. Hodges (though Mississippi did not have its same-sex adoption ban struck down by a federal court until March 2016). Policies regarding adoption vary greatly between jurisdictions. Some states allow adoption by all couples, while others ban all unmarried couples from adoption.Hate crimes based on sexual orientation or gender identity are punishable by federal law under the Matthew Shepard and James Byrd, Jr. Hate Crimes Prevention Act of 2009, but many states lack state-level hate crime laws that cover sexual orientation and/or gender identity. LGBT people of color face the highest rates of discrimination and hate crimes, especially trans women of color.Civil rights for LGBT people in the United States are advocated by a variety of organizations at all levels and concentrations of political and legal life, including the Human Rights Campaign, Lambda Legal, GLBTQ Legal Advocates & Defenders (GLAD), American Civil Liberties Union (ACLU), the National Center for Transgender Equality, and the National Center for Lesbian Rights.