Russia's competition watchdog fined Alphabet's Google 2 billion roubles ($34.2 million) on Tuesday for abusing its dominant position in the video hosting market, the regulator said in a statement.
The decision is the latest multi-million dollar fine as part of Moscow's increasingly assertive campaign against foreign tech companies.
The Federal Antimonopoly Service (FAS) said the company had "abused its dominant position in the YouTube video hosting services market", without providing additional details.
"We will study the text of the official decision to define our next steps," Google said in a statement to Reuters.
Google must pay the fine within two months of it entering into force, the FAS said.
Russia has slapped Google's Russian subsidiary with numerous fines in recent months. Last week a court ordered it to pay 21.1 billion roubles ($358.7 million) over what prosecutors said were repeated refusals to remove content Russia deems illegal, such as "fake news" about Russia's invasion of Ukraine.
Since Moscow launched what it calls its "special military operation" in Ukraine, it has also accelerated attacks on Western tech companies at home in a push to exert more control over the online space, including through supporting domestic players to oust their Western rivals.
Gazprom Media - a media conglomerate linked to state-controlled gas giant Gazprom - has been heavily promoting RuTube, its Russian alternative to YouTube, which has seen a sharp uptick in traffic since February.
YouTube, which has blocked Russian state-funded media globally, is under heavy pressure from Russia's communications regulator and politicians.
Google stopped selling online advertising in Russia in early March but has kept some free services available. Its Russian subsidiary officially filed for bankruptcy after authorities seized its bank account, making it impossible to pay staff and vendors.