Immediately after the birth of Sergei, the Tsivilyov family began to live in the city of Kotlas, Arkhangelsk Oblast in Russia.

In 2007, he co-founded the Lenexpoinvest company, which was supposed to build a new Lenexpo complex - where, in particular, the St. Petersburg International Economic Forum is held annually.

Since 2014, he was the CEO of the Kolmar company and the owner of 70% of its shares (the remaining 30% through the Volga Group belong to the entrepreneur Gennady Timchenko).

[2] On 29 April 2019, at a hardware meeting, he threatened the nurses of the Anzhero-Sudzhensk city hospital, who went on a hunger strike against the mass layoff of medical staff.

Declaring the inadmissibility of holding "rallies and strikes" in the field, he turned to the prosecutor's office and the police with a request to take tough measures against the hunger strikers.

In 2022, amid the Russian invasion of Ukraine, Tsivilyov initiated a campaign to refer to the region in official documents as "КуZбасс" (KuZbass), incorporating the Latin letter Z used as a pro-war symbol.

[14][15][16] Tsivilyov is married to Anna Evgenievna Putina, a daughter of Vladimir Putin's cousin,[17] who in March 2017 received a 70% stake in Kolmar Group LLC.

[20] On 21 July 2022, amid Russia's invasion of Ukraine, Tsivilyov was sanctioned by the European Union for spreading Russian disinformation.