- The following is a list of secrets, Easter eggs, and hidden trivia references in Grand Theft Auto III.
- In the very southwestern block of Bedford Point lies a parking lot (notably featured in the Kingdom Come mission) where an Easter egg can be located, known as The Hidden Sign. To reach it, the player needs a small-sized car such as Manana or Taxi. Going up the stairs leading to an overlooking platform to the north of the lot (near the entrance to an underground parking in the same area), the player must jump from the car to reach the top of a building to the west, jump down on the wall, and from there, drop down to an otherwise inaccessible alley behind it. At the end of the alley, on the wall, there is a posted notice that states "You werent supposed to be able to get here you know" [sic]. Near the poster is a ramp that allows the player to leave again.
- If you leave the city limits of Liberty City by using the Dodo and fly straight north for a few minutes, you can see various Rockstar Games' programmers edited to look like town names on the mini-map, e.g. Obbeburgh (Obbe Vermeij), Aaronsville (Aaron Garbut), Woodcunty (Alisdair Wood), Les County (Leslie Benzies), Garystown (Gary McAdam) and Adamton (Adam Fowler or Adam Cochrane). However, these towns don't physically exist within the game world, and only their names can be seen on the radar.
- There is a billboard that says "See you in Miami!" hinting at where the next game would take place: Grand Theft Auto: Vice City, based on Miami.
- Some shops in the Red Light District close at midnight until morning, when they will open shop and take up the blinds.
References to previous games
- Top Down City is a fictional film in GTA III. Ads can be spotted all over the city. The film refers to the top-down perspective games Grand Theft Auto 1 and Grand Theft Auto 2.
- Inside of the TW@ Internet Cafe, there are computers on the first floor displaying screenshots of GTA 1 and GTA 2.
References to other games
- On the in-game radio, you can hear references to Carcer City, a city later used in Rockstar's Manhunt.
- In the mission Two-Faced Tanner, the character that the player has to kill is named Tanner, protagonist of the Driver series. Humorously, he was given a female walking animation due to the criticism that Tanner in Driver walked like a girl.
- Badfellas is another film advertised in GTA III. It is a parody of the film Goodfellas which Frank Vincent, the voice of Salvatore Leone starred in.
- Rockstar Games are known for hiding their logo in secret places in their games. There is, however, a poorly disguised Rockstar Games logo on top of a unusable helicopter on the roof of Kenji's Casino. The logo is poorly disguised because it even reads "Rockstar Games" below it. The logo can also be found on a hat of the pedestrian that wears headphones (and is famous for the mysterious tune heard through them).
- In Staunton Island, there is a store with a banner above its enterance. The banner is a Rockstar Games' self-advertisement banner as it reads "GTA 3 OUT NOW" and "WWW.ROCKSTARGAMES.COM."
- There is a particular construction worker pedestrian that can be found in the game, and when bumped into, he will say segments of the song "YMCA" by Village People. This is an Easter egg, as the lead singer in that song also is a white construction worker. The man is heard speaking various phrases such as "Young man," "There's no need to be down" and "I'm in the YMCA".
- Car stuck in Liberty City underground. This is what looks like a 20th-century car getting stuck when the underground was build.
- The yellow notebooks carried by male students of Liberty Campus feature scribbled drawings of ejaculating male genitalia.
- In a football stadium in Stanton Island, the crowds in it are making the word, "Cocks."