Watch Dogs (stylized as WATCH_DOGS) is an open world action-adventure video game developed by Ubisoft Montreal and published by Ubisoft. It was released worldwide on 27 May 2014 for Microsoft Windows, PlayStation 3, PlayStation 4, Xbox 360 and Xbox One, while a Wii U version was released on 18 November 2014 in North America, 21 November in Europe, and 4 December in Japan.[10] Set within a fictionalized version of Chicago, Illinois, the single-player story follows a hacker and his efforts to seek revenge after the accidental death of his niece. The open world design lets players freely roam Chicago, which includes the urban city, open countryside, and slums.

The game is played from a third-person perspective and its world is navigated on-foot or by vehicle. Players control Aiden Pearce, a highly skilled grey hat hacker who can hack into the "ctOS", a centralized operating system which manages the hyper-connected city of Chicago, and formed after a Northeast blackout of 2003 was caused by a hacker. An online multiplayer mode is also provided in the game, allowing up to eight players to engage in both cooperative and competitive gameplay in a recreation of the single-player setting.

Development on the game began in 2009. As part of their research for the open world, the developers conducted field research around Chicago throughout development and captured footage for the design team. Development duties were shared between many of Ubisoft's studios worldwide.

Following its announcement in June 2012, Watch Dogs was widely anticipated. At release, it received generally positive feedback, with praise particularly directed at the game's hacking elements and mission variety. The game also received criticism concerning the gameplay and some technical issues. Watch Dogs was a commercial success, breaking the record for the biggest first day sales of a Ubisoft game, and becoming the biggest launch of a new IP ever in the United Kingdom at the time. Within a week, the game sold over 4 million copies.