Sergei Tikhanovsky is a Belarusian YouTuber, video blogger, opposition leader and pro-democracy activist. He is primarily known for his activism against the government of Belarus's long-serving president, Alexander Lukashenko. In May 2020, he announced his intention of running for the 2020 presidential election, but he was arrested two days after the announcement, and his wife Sviatlana Tsikhanouskaya then ran in place of him as the main rival to Lukashenko in the contested election. On 21 June 2025, Tsikhanouski was released from prison after US representative Keith Kellogg's visit to Belarus, after five years of solitary confinement.