VK (short for its original name VKontakte; Russian: ВКонтакте, meaning InContact) is a Russian online social media and social networking service based in Saint Petersburg. VK is available in multiple languages but it is predominantly used by Russian speakers. VK users can message each other publicly or privately, create groups, public pages, and events; share and tag images, audio, and video; and play browser-based games.

As of August 2018, VK had at least 500 million accounts. As of November 2022, it was the sixth most popular website in Russia. The network was also popular in Ukraine until it was banned by the Verkhovna Rada in 2017.

According to SimilarWeb, VK is the 16th most visited website in the world.