Cyber Partisans (Belarusian: Кіберпартызаны, romanized: Kiberpartyzany, Russian: Киберпартизаны, romanized: Kiberpartizany) is a Belarusian decentralized anonymous hacktivist collective that emerged in September 2020, known for its cyber attacks against the governments of Belarus and Russia. The group is part of the broader Belarusian opposition movement.

Cyber Partisans consists of a group of Belarusian IT workers who live abroad. In an August 2021 interview to Bloomberg, hackers shared some details about themselves: they are 15 people, none of whom are professional hackers; of them, only 3 or 4 perform the hacks, others deal with the analysis of obtained data; and some group members were penetration testers before joining the group. Members are anonymous even to each other. The group describes its activities as ethical hacking, as it goes only against the state and do not harm to ordinary citizens. In late January 2022, the group reportedly consisted of some 30 people. Its spokesperson, Yuliana Shemetovets, is based in New York.

An anonymous spokesperson for the group told in an interview to MIT Technology Review: "What we want is to stop the violence and repression from the terroristic regime in Belarus and to bring the country back to democratic principles and rule of law." In 2021 and 2022, the group affirmed that it was not collaborating with any foreign government, but "we are not against it, as long as it aligns with our depicted goals, to change the regime."

The Cyber Partisans originated in September 2020 after the 2020 Belarusian presidential election and subsequent protests against its falsification by Alexander Lukashenko. The protests were brutally suppressed by the government's police and security forces.

Initially, actions by the group were symbolic: group members hacked state news websites (All-National TV, Belarus-1) and streamed videos showing scenes of police brutality, and inserted the names of Lukashenko and the minister of Internal Affairs, Yury Karayeu, to a police most wanted list. The group also hacked government websites to add the white-red-white flag, which is favored by the Belarusian dissidents, over the official red and green flag of the country.

Cyber Partisans work together with the BYPOL group, which consists of former Belarusian police officers working against Lukashenko's government. Their knowledge of database structure helps to plan and execute the Partisans' moves.

In July 2021, Cyber Partisans cracked the Ministry of Internal Affairs' most sensitive databases. The group obtained a large volume of material, includes the archive of almost 2 million minutes of secretly recorded phone conversation audio; lists of alleged police informants; personal information about top government officials; and video footage gathered from police drones and detention centers. The group also obtained the databases for passports, all registered motor vehicles, recordings from the cameras in the Okrestina prison's isolation cells, and mortality statistics. The group shared these data with the journalists who calculated the excess mortality during the COVID-19 pandemic in Belarus. They concluded that from March 2020 to March 2021, this figure was 32,000 people, 14.4 times more than the authorities reported. The group published passport data of Lukashenko and his sons to prove that they really hacked that database. The authenticity of the data was also demonstrated by data on journalists from Current Time TV, which the Partisans provided to Current Time at the outlet's request to prove the veracity of the leak.

During the 2022 Russian invasion of Ukraine, Cyber Partisans was one of three main Belarusian dissident groups that worked to stymie the Belarusian involvement in the Russian invasion, specifically by targeting railroad supply lines. (The other groups were Belarusian railway workers and defectors from the government's security forces). Cyber Partisans launched the first attack on the railway's systems in late January 2022, in the days immediately before the invasion slowing the movement of Russian troops before they had crossed the border. The group said that it had penetrated the Belarusian Railway's network system the previous month, in December 2021. A spokesperson for Cyber Partisans said that the railway company's system was vulnerable and ran on an outdated Windows XP operating system. The group used a modified form of ransomware to paralyze the railway system, saying that it would return to computer network to normal if the Belarusian government released 50 political prisoners in need of medical treatment and stopped Russian forces from entering Belarus. Partisans cracked and encrypted internal databases of the railway. The group targeted freight rail to disrupt Russian military movements and cargo bound for China; the group said that it deliberately avoided affecting passenger rail.