Silk Road was an online black market and the first modern darknet market. It was launched in 2011 by its American founder Ross Ulbricht under the pseudonym "Dread Pirate Roberts". As part of the dark web, Silk Road operated as a hidden service on the Tor network, allowing users to buy and sell products and services between each other anonymously. All transactions were conducted with bitcoin, a cryptocurrency which aided in protecting user identities. The website was known for its illegal drug marketplace, among other illegal and legal product listings.

Between February 2011 and July 2013, the site facilitated sales amounting to 9,519,664 bitcoins.

In October 2013, the Federal Bureau of Investigation (FBI) shut down the Silk Road website and arrested Ulbricht. Silk Road 2.0 came online the next month, run by other administrators of the former site, but was shut down the following year as part of Operation Onymous. In 2015, Ulbricht was convicted in federal court for multiple charges related to operating Silk Road and was given two life sentences without possibility of parole. He was pardoned by President Donald Trump in 2025.

The website was launched in February 2011; development had begun six months prior. The name "Silk Road" comes from a historical network of trade routes started during the Han Dynasty (206 BCE – 220 CE) between Europe, India, China, and many other countries on the Afro-Eurasian landmass. Silk Road was operated by the pseudonymous "Dread Pirate Roberts" (named after the fictional character from The Princess Bride), who was known for espousing libertarian ideals and criticizing regulation.

Two other individuals were also closely involved in the site's growth and success, known as Variety Jones and Smedley.

In June 2011, Gawker published an article about the site which led to an increase in notoriety and website traffic. U.S. Senator Chuck Schumer asked federal law enforcement authorities to shut it down, including the Drug Enforcement Administration (DEA) and Department of Justice.

In May 2013, Silk Road was taken down for a short period of time by a sustained DDoS attack. On 23 June 2013, it was first reported that the DEA seized 11.02 bitcoins, then worth a total of $814, which the media suspected was a result of a Silk Road honeypot sting. The FBI has claimed that the real IP address of the Silk Road server was found via data leaked directly from the site's CAPTCHA and it was located in Reykjavík, Iceland.

IT security experts have doubted the FBI's claims because technical evidence suggests that no misconfiguration that could cause the specific leak was present at the time.

Due, in part, to off-duty research conducted by IRS Criminal Investigation Special Agent Gary Alford, Ross Ulbricht was alleged by the FBI to be the founder and owner of Silk Road and the person behind the pseudonym "Dread Pirate Roberts" (DPR). Alford searched for any mentions of the .onion URL or .tor address, stating that someone might have advertised or suggested the marketplace on Google. The first mention of the website was by a user named "altoid".

Further searching into this altoid profile led him to a post about an open position that told interested applicants to contact what was Ross Ulbricht's personal email. He was arrested on 1 October 2013 in San Francisco in Glen Park Library, a branch of the San Francisco Public Library. During the arrest, the FBI seized Ulbricht's laptop which he was using to connect to the servers and manage the marketplace.

Ulbricht was indicted on charges of engaging in a continuing criminal enterprise, distributing narcotics, distributing narcotics by means of the Internet, and four conspiracy charges related to distribution of narcotics, computer hacking, money laundering, and false identity documents. He was separately indicted for a single murder-for-hire charge. Prosecutors alleged that Ulbricht paid $730,000 to others to commit the murders, although none of the murders actually occurred. Ulbricht ultimately was not prosecuted for any of the alleged murder attempts.

The FBI initially seized 26,000 bitcoins from accounts on Silk Road, worth approximately $3.6 million at the time. An FBI spokesperson said that the agency would hold the bitcoins until Ulbricht's trial finished, after which the bitcoins would be liquidated. In October 2013, the FBI reported that it had seized 144,000 bitcoins, worth $28.5 million, and that the bitcoins belonged to Ulbricht. On 27 June 2014, the U.S. Marshals Service sold 29,657 bitcoins in 10 blocks in an online auction, estimated to be worth $18 million at contemporary rates and only about a quarter of the seized bitcoins.

Another 144,342 bitcoins were kept which had been found on Ulbricht's computer, roughly $87 million. Tim Draper bought the bitcoins at the auction with an estimated worth of $17 million, to lend them to a bitcoin start-up called Vaurum which is working in developing economies of emerging markets.

Ulbricht's trial began on 13 January 2015 in federal court in Manhattan. At the start of the trial, Ulbricht admitted to founding the Silk Road website, but claimed to have transferred control of the site to other people soon after he founded it. Ulbricht's lawyers contended that Dread Pirate Roberts was really Mark Karpelès, and that Karpelès set up Ulbricht as a fall guy. However, Judge Katherine B. Forrest ruled that any speculative statements regarding whether Karpelès or anyone else ran Silk Road would not be allowed, and statements already made would be stricken from the record.

In February 2013, an Australian cocaine and MDMA ("ecstasy") dealer became the first person to be convicted of crimes directly related to Silk Road, after authorities intercepted drugs that he was importing through the mail, searched his premises, and discovered his Silk Road alias in an image file on his personal computer. Australian police and the DEA have targeted Silk Road users and made arrests, albeit with limited success at reaching convictions.

In December 2013, a New Zealand man was sentenced to two years and four months in jail after being convicted of importing 15 grams of methamphetamine that he had bought on Silk Road.

23-year-old Dutch drug dealer Cornelis Jan Slomp pled guilty to large-scale selling of drugs through the Silk Road website, and was sentenced in Chicago to 10 years in prison on 29 May 2015 with his attorney, Paul Petruzzi, present. Dealer Steven Sadler was sentenced to five years in prison. There have been over 130 other arrests connected with Silk Road, although some of these arrests may not be directly related to Silk Road, and may not be public information for legal reasons.

On 3 November 2020, after years of inactivity, observers of the bitcoin blockchain detected that two transactions totaling 69,370 bitcoin and bitcoin cash, worth approximately $1 billion in total at the time of transfer, had been made from 1HQ3Go3ggs8pFnXuHVHRytPCq5fGG8Hbhx, a bitcoin address associated with the Silk Road. At the time of transfer, it was worth 58 times its value in 2015. It was subsequently revealed that the transfer had been made by the United States government in a civil forfeiture action. According to a press release by the U.S.

Attorney's Office of the Northern District of California, the bitcoin wallet belonged to an "Individual X" who had originally acquired the bitcoins by hacking the Silk Road.