In all canons, ACME Headquarters is primarily located in San Francisco and the leader of ACME is called "The Chief". Carmen Sandiego was a brilliant agent for the ACME Detective Agency until she left and formed the Villains' International League of Evil (V.I.L.E.). V.I.L.E. seeks to commit incredible thefts and/or cause chaos in other ways, while ACME tries to thwart them and capture their agents. In the computer games, the thefts of the minor henchmen are almost always meant to keep ACME occupied before Carmen herself pulls off the real crime, usually something monumental and significant to the theme of the game. Carmen is incredibly, at times almost supernaturally, elusive and her permanent capture would be ACME's holy grail.
Carmen Sandiego was voiced by Rita Moreno in the Earth animated series. This animated television series reveals a unique backstory about Carmen Sandiego. According to this canon, Carmen Sandiego was an orphan raised at the Golden Gate Girls' School in San Francisco. The Chief gave her a home at the ACME Detective Agency and, by age seventeen, she solved more cases than any other ACME agent. However, she then disappeared and turned to a life of crime. Her partner when she was at ACME was a Japanese man named Suhara, who left ACME after she did and appears to now be retired. Unlike in most of the rest of the series, the reason for Carmen leaving ACME is not specifically stated, although it is speculated by Suhara ("Déjà Vu"). In the latter seasons of the show, Carmen began to be portrayed as more of an anti-hero than a proper villainess, even teaming up with the show's protagonists to defeat criminals more unscrupulous than herself on several occasions. Additionally, it was made clear that she makes a point of refusing to steal something if the theft will cause anybody harm—a vow she frequently breaks outside this canon.
The Earth series gave the franchise a timeline, with the mid-1990s (the time the show was produced) being the present. According to this timeline, Carmen joined ACME in 1985, placing her birth in approximately 1968. Her birthday is on March 1 ("The Scavenger Hunt"). In the two-part finale, Carmen Sandiego attempts to rob millionaire Malcolm Avalon of a statue but finds a portrait of someone who she believes is her mother based on a locket she owns and sparks the possibility that Avalon might be her father. Avalon refuses to believe that she is his daughter due to her propensity of being a thief and that he believes his daughter died in a hotel fire along with her mother in San Francisco. However, later on in the episodes he accepts the possibility that she might be his daughter. Before finding out the ultimate truth, Avalon falls from a roof during a battle with former ACME agent Lee Jordan and has selective amnesia of the events that have transpired. At the end of the final episode, Carmen hires a hypnotist in order to remember what happened the day of the fire. It is discovered she picked the locket off the ground, but cannot recall if it was because she dropped it, or if she found it while the hotel was burning. The finale ends with her saying, "But maybe there are just some things we aren't meant to know for sure."
According to the episode "Hot Ice", Carmen has been gone from ACME for 10 years, 3 months and 7 days.
Unlike in most of the rest of the franchise, the reason for Carmen leaving ACME is not specifically stated in the Earth series, although it was speculated by Suhara ("Déjà Vu"). In the episode "Hot Ice", Carmen points out she didn't have all the high-tech hardware Zack and Ivy have back when she was an ACME detective. In the episode "Retribution, Part 1" a scene shown in flashback shows how justified she was. This is further enforced in another episode, where Carmen is dared to try something without any of her high-tech equipment. She agrees to this, and actually pulls it off, hijacking the Orient Express with only conventional tools. Carmen is sometimes depicted as genuinely liking Zack and Ivy, and enjoying the ongoing battle of wits she has with them to the point where she will often congratulate the two for their successes regarding them as worthy opponents. Carmen thievery skills are highly complex as she as managed to steal the Mona Lisa's smile, technology to steal musical talent and even the entire beach of Kaimu Beach in Hawaii. Despite her nature as a thief, Carmen does have her nice moments. In one episode, Carmen eludes every ACME Detective at once, the detectives find that she has left them all a doll of herself that teases that it is the only Carmen that they'll catch, and wishes a Merry Christmas as a Christmas gift. In the episode "Trick or Treat" Zack and Ivy find Carmen's Halloween party. They see Sara Bellum handing out candy to trick-or-treaters, on Carmen's orders so her theft wasn't going to wreck the holiday for children. Although a villainess Carmen operates on her own brand of morals, such as being a thief in the strictest sense of the word and not killing Zack and Ivy despite gaining many opportunities to do so. She has even saved the Chief’s life when he was suffering a viral malfunction and did not want to lose him and only had Manny "kidnap" him so she could get to play chess with him like they did every Christmas when she was an ACME agent.
The six Carmen Sandiego games produced from 1996 through 1999 (Where in the World is Carmen Sandiego?, Where in the U.S.A. is Carmen Sandiego?, Where in Time is Carmen Sandiego? (Carmen Sandiego's Great Chase Through Time), Carmen Sandiego Word Detective, Carmen Sandiego Math Detective and Carmen Sandiego's ThinkQuick Challenge) seem to form a loose canon as they feature some of the same characters. However, characters as well as some other elements often appear differently between the games due to the use of different animation styles. It is only in Word Detective and Math Detective that substantial information about Carmen is given. In this universe, Carmen's partner when she was at ACME was Chase Devineaux and one of the last cases they worked on together involved the mythical "Prometheus Rock." Although Chase and Carmen apprehended the thieves responsible for stealing it, the rock itself was not found. When Carmen left ACME, Chase was forced to leave ACME as well since he had worked so closely with her. However, Chase began working with ACME again to stop Carmen's plan to steal language with the Babbel-On Machine, as depicted in Carmen Sandiego Word Detective. In Carmen Sandiego Math Detective, the whereabouts of the Prometheus Rock became all too clear when Carmen tried to use it to make herself all-powerful, although her plans were thwarted by Agent 9 (the player) and Chase. As of Carmen Sandiego's ThinkQuick Challenge, Chase is again working for ACME.
In the Carmen Sandiego Treasures of Knowledge canon, Carmen Isabella Sandiego was a child prodigy, who won a substantial amount of money on a game show called It's a Wise Child (a reference to J. D. Salinger's Glass family in Franny and Zooey and many of his short stories) when she was ten years old. She used the money to travel extensively around the world until she was twelve. Her partner when she was at ACME was Jules Argent, who still works for ACME and appears to be in her early twenties. Jules specifically notes that Carmen never talked about her childhood, and aside from the mention of her winning the aforementioned game show, no details of it are given. (Where in the World is Carmen Sandiego? Treasures of Knowledge) The game show Carmen wins may be a reference to the game shows the character herself starred in.
According to Where in the Universe is Carmen Sandiego?, her favorite writer is Ursula K. Le Guin and her favorite astronomer is Nicolaus Copernicus.
In Carmen Sandiego: Junior Detective Edition, the third version of Where in the World is Carmen Sandiego? and Where in the World is Carmen Sandiego? Treasures of Knowledge, Carmen owns a red helicopter. In Junior Detective and in the 1996 versions of World and U.S.A., she owns a pet cat named Carmine.
- Carmen Sandiego will make her first debut in Danny's Adventures of Tom and Jerry: The Movie.
- Carmen Sandiego will appear in Barney's Adventures of Muppets Most Wanted. At the end, she takes over the title of "World's Number One Most Wanted Criminal", ending Constantine's relationship with her.
- SPOILER ALERT: Carmen Sandiego is the shadowy figure who will be working with Lord Zedd and his group in Lilo & Stitch's Adventures, Twilight Sparkle's Adventures and Sonic's Adventures.
- Later in Lilo & Stitch's Adventures, a Cadmus clone of Carmen Sandiego will be made by Amanda Waller to become a good guy and an ACME agent as the real Carmen's replacement.
- The original Carmen Sandiego would be surprised about the clone, yet she would love a good challenge from a tricky-to-evade ACME agent.