The Pirate Bay, commonly abbreviated as TPB, is a freely searchable online index of movies, music, video games, pornography and software. Founded in 2003 by Swedish think tank Piratbyrån, The Pirate Bay facilitates the connection among users of the peer-to-peer torrent protocol, which are able to contribute to the site through the addition of magnet links. The Pirate Bay has consistently ranked as one of the most visited torrent websites in the world.

Over the years the website has faced several server raids, shutdowns and domain seizures, switching to a series of new web addresses to continue operating. In multiple countries, Internet service providers (ISPs) have been ordered to block access to it. Subsequently, proxy websites have emerged to circumvent the blocks.

In April 2009, the website's founders Fredrik Neij, Peter Sunde and Gottfrid Svartholm were found guilty in the Pirate Bay trial in Sweden for assisting in copyright infringement and were sentenced to serve one year in prison and pay a fine. They were all released by 2015 after serving shortened sentences.

The Pirate Bay has sparked controversies and discussion about legal aspects of file sharing, copyright, and civil liberties and has become a platform for political initiatives against established intellectual property laws as well as a central figure in an anti-copyright movement.