One of the camera feeds that the player can hack into shows a father watching his son play a video game. The father is mocking how the assassin in the game talks to the people he kills. This is a reference to the Assassin's Creed series (also developed by Ubisoft), in which the protagonists talk to the people they kill before they die.

T-Bone is shown to own both Assassin's Creed II and Far Cry 3, two other Ubisoft titles.

During one of the gameplay trailers, a man can be seen dancing in his apartment. His information states he is a video game store clerk and has legally changed his name to "Eddie Kenway". This suggests the man is a fan of Assassin's Creed IV: Black Flag, as Edward Kenway is the name of the main protagonist in that game.

Inside Nicole Pearce's house is a Rayman Raving Rabbid toy that laughs when hacked.

Every sign in the game reveals a famous meme or quote when hacked.

Aisha Tyler (famous for her role of Lana Kane in the animated comedy Archer) makes a cameo appearance as herself in the role of a citizen NPC. She can be discovered while exploring Chicago, but can be easily found in Connely Square just outside of the Willis Tower in the mission "A Wrench in the Works". She is also the subject of a Privacy Invasion activity.

Graffiti can be found around the city that resembles the Slenderman.

During one of the optional Privacy Invasions, the player can see an emotional discussion between a stage II cancer patient and a woman working two jobs. The conversation and characters themselves are a direct reference to the TV series Breaking Bad.

Inside Iraq's hideout are a number of arcade machines featuring the logo of Far Cry 3: Blood Dragon.

In some randomly generated vehicles, there is a chance that the keys will have a keychain of what appears to be a My Little Pony character dressed as Aiden.

While modding the PC version, a user by the name of "The Worse" found almost all of the shaders and graphical improvements present in the 2012 and 2013 trailers for the game. It's possible that the PC version's graphics were downgraded so that it would not make the PlayStation 4 and Xbox One versions look drastically inferior by comparison.

The town Pawnee is based on the real life town of the same name. However, the game portrays Pawnee as being located right outside of Chicago, when it is actually located near central Illinois.

In the mission shown during the gameplay demo shown at E3 2012, Aiden is shown killing Joseph Demarco. The mission was changed prior to release, and instead killing Demarco, Spoiler:Aiden now has to kill a hacker, Defalt.

At the Farris Halstead Library train station in the Loop, if you follow the tracks to the east, you will discover a junction where opposing straight tracks from the north and south intersect with the eastward tracks. These eastward straight tracks are unusual in that they seem to continue and stop before the edge of the elevated platform with no bumpers to mark the end of it, appearing unfinished. It should be noted though that no trains traveling eastward will actually go down these straight tracks all the way due to the curved transition tracks guiding them away. In the real-life Loop in Chicago, this spot would be located at the junction right after the Harold Washington Library train station, which unlike its depiction in Watch Dogs has no straight tracks continuing after the curved tracks at all.

This detail is notable because the day before Watch Dogs' release in May 2014, an anonymous developer claiming to have worked on the game posted to 4chan their insight on the game's development and experience working with Ubisoft Montreal, including details on how the train tracks worked in earlier builds of the game that may be talking about this unfinished intersection:


In 2020, an early build of the game dated to September 21, 2013 was dumped online by YouTuber JustAnyone, but it's currently unknown if this mistake existed in this build.