The game had been scheduled to launch November 22 for Xbox 360, PS3, Xbox One and PC, with the PS4 version to follow alongside the console's launch.
It now won't launch any sooner than April 2014.
Watch Dogs development team released the following statement:
“Our ambition from the start with Watch_Dogs has been to deliver something that embodies what we wanted to see in the next-generation of gaming. It is with this in mind that we've made the tough decision to delay the release until Spring 2014,
“We know a lot of you are probably wondering why now? We struggled with whether we would delay the game. But from the beginning, we have adopted the attitude that we will not compromise on quality. As we got closer to release, as all the pieces of the puzzle were falling into place in our last push before completion, it became clear to us that we needed to take the extra time to polish and fine tune every detail so we can deliver a truly memorable and exceptional experience.
“We would like to take this opportunity to thank all of you. We thoroughly enjoy and appreciate the way you respond on the web, at events, press conferences and during other opportunities we have to interact. Your passion is what drives us.
“We can't wait to see you in Chicago next Spring. We are confident you’ll love this game as much as we love working on it.”