Ruby Ridge was the site of an eleven-day siege in 1992 in Boundary County, Idaho, near Naples. It began on August 21, when deputies of the United States Marshals Service (USMS) initiated action to apprehend and arrest Randy Weaver under a bench warrant after his failure to appear on firearms charges. Given three conflicting dates for his court appearance, and suspecting a conspiracy against him, Weaver refused to surrender, and members of his immediate family, and family friend Kevin Harris, resisted as well. The Hostage Rescue Team of the Federal Bureau of Investigation (FBI HRT) became involved as the siege developed.

During the USMS reconnoiter of the Weaver property, six U.S. Marshals encountered Harris and Weaver's 14-year-old son, Sammy, in woods near the family cabin. A shootout took place. Deputy U.S. Marshal William Francis Degan, Sammy Weaver, and the Weavers' dog, Striker, all died as a result. In the subsequent siege of the Weaver residence, led by the FBI, Weaver's wife Vicki was killed by FBI sniper fire. All casualties occurred in the first two days of the operation. The siege and standoff were ultimately resolved by civilian negotiators. Harris surrendered and was arrested on August 30, while Weaver and his three daughters surrendered the next day.

Randy Weaver and Kevin Harris were subsequently arraigned on a variety of federal criminal charges, including first-degree murder for the death of Degan. Harris was acquitted of all charges, and Weaver was acquitted of all charges except for the original bail condition violation for the firearms charges and for having missed his original court date. He was fined $10,000 and sentenced to eighteen months in prison, credited with time served plus an additional three months, and released after sixteen months.During the federal criminal trial of Weaver and Harris, Weaver's attorney, Gerry Spence, made accusations of criminal wrongdoing against the agencies involved in the incident, in particular the FBI, the USMS, the Bureau of Alcohol, Tobacco, and Firearms (ATF), and the United States Attorney's Office (USAO) for Idaho. At the trial's end, the Department of Justice's Office of Professional Responsibility formed the Ruby Ridge Task Force (RRTF) to investigate Spence's charges. A redacted HTML version of the RRTF report, publicly released by Lexis Counsel Connect, raised questions about all the participating agencies' conduct and policies. The Justice Department later posted a more complete PDF version of the report.Both the Weaver family and Harris brought civil suits against the federal government over the firefight and siege. The Weavers won a combined out-of-court settlement in August 1995 of $3.1 million. After numerous appeals, Harris was awarded a $380,000 settlement in September 2000.

To answer public questions about Ruby Ridge, the Senate Subcommittee on Terrorism, Technology and Government Information held hearings between September 6 and October 19, 1995, and subsequently issued a report calling for reforms in federal law enforcement to prevent a repeat of the losses of life at Ruby Ridge and restore public confidence in federal law enforcement. It was noted that the Ruby Ridge incident and the 1993 Waco siege involved many of the same agencies (FBI HRT and ATF) and some of the same personnel (the FBI HRT commander). The Government Accountability Office (GAO) also conducted a review of federal policies about use of deadly force, publishing it in 1995.

In 1997, the Boundary County prosecutor indicted FBI HRT sniper Lon Horiuchi for manslaughter before the statute of limitations for the charge could expire; the case, Idaho v. Horiuchi, was moved to federal court, which has jurisdiction over federal agents. The case was dismissed because of the supremacy clause. The United States Court of Appeals for the Ninth Circuit ruled in 2001 that Horiuchi could be tried on state charges. A new county prosecutor, Brett Benson, had been elected in 2000 and dismissed the case, saying it was unlikely the state would be able to prove the criminal charges. Benson's decision was controversial.The events that took place at Ruby Ridge, and the law enforcement response during the Waco siege roughly six months later, have been cited by commentators as catalysts for the Oklahoma City bombing by Timothy McVeigh and Terry Nichols.