Fun fact: yes, there are two Kansas Cities. And yes, the important one is in Missouri, not Kansas. Don't let anyone confuse you on this.
Despite this, when people refer to "Kansas City," they generally mean the entire metropolitan area, which possesses a population of a little more than two million people between Missouri and Kansas. Certainly, most works of fiction don't make it a point of drawing the distinction between Kansas City, Kansas and Kansas City, Missouri.
The Missouri KC, often nicknamed "KCMO" (pronounced K-C-Moe), contains most of what people think of when they think of Kansas City. That includes the two major sports franchises in the area (Major League Baseball's Royals and the National Football League's Chiefs), the architecture and the culture. It features more fountains than any city in the world, save Rome, and more boulevards than any city in the world, save Paris.
"KCK" (the Kansas side) is home to Sporting Kansas City of Major League Soccer and Kansas Speedway, the region's outpost in NASCAR. Many residents of the region live in the absurdly wealthy suburbs on the Kansas side and commute to KCMO proper for work.
The city is famous in part for its jazz, in part for its barbecue and in part for its Mafia. Kansas City played a small, but not unimportant role in the country's racial drama during the early-to-mid 20th century. Jackie Robinson, who broke Major League Baseball's color barrier, played with the Kansas City Monarchs of the Negro League before signing with the Brooklyn Dodgers. The Negro League Baseball Museum sits at the famous intersection of 18th and Vine St. where the aforementioned race, crime and music came together. 12th Street and Vine, as the song "Kansas City" suggests, was at one time an even more happening place, but part of Vine was removed ,and there's now a park where it used to cross 12th.
Kansas City also plays a small role in film history as the place where Walt Disney began his animation career (It's said that a mouse in his film studio gave him the inspiration for Mickey Mouse). Many of the locals he hired - Ub Iwerks, Friz Freleng, Hugh Harman and Rudolf Ising - went on to successful careers as well.
The city is home to Hallmark greeting cards, which, depending on your outlook dispenses Heartwarming Moments or mountains of sap. Other major international corporations such as Sprint, Garmin, H&R Block, and AMC Theaters are also based in Kansas City.
Harry Truman was from nearby Independence and spent much time in KC as a younger man.
Currently the area is the envy of anyone who wants the fastest Internet connection in the country, as Google chose the Kansas Cities to be the first test market for their ultra fast Google Fiber network. The city also is the home of Linda Hall Library, the world's largest independently funded public library specifically dedicated to science, engineering and technology.
Kansas City in fiction:
- Robert Altman's 1996 film Kansas City is about... well, the setting is certainly obvious. It emphasizes the crime and the jazz. Altman himself was a Kansas City native.
- The city plays a tangential role in the mafia flick Casino. While the movie is set in Las Vegas, the characters repeatedly refer to the bosses "back in Kansas City," and a small handful of scenes take place in a Kansas City restaurant.
- The song "Kansas City" (featuring the famous lyrics "Kansas City/Kansas City here I come"), obviously.
- Todd the call center manager from Outsourced is from Kansas City. The town's barbecue is referenced a handful of times (he unsuccessfully tries to import some ribs), and one episode revolves around his attempts to catch a Chiefs game in India.
- The X-Files episode "Fight Club" takes place in Kansas City.
- The UPN sitcom Malcom & Eddie was set in Kansas City.
- Captain Carrot and His Amazing Zoo Crew! mentioned on occasion its Earth-C counterpart, "Kornsas City," including where Timmy Joe Terrapin (aka Fastback) was heading in search of work just before gaining superpowers. Earth-C's version of the song "Kansas City" is also seen here, as well as mention of the nearby small town of "Abalone" (Earth-C's Abilene, Kansas).
- In the Drawn Together episode where Xander roleplays to prepare to come out to his parents, Foxxy Love tells him to go to an orphanage in Kansas City, Missouri on her behalf to apologize to her son for abandoning him.
- United States of Tara takes place in Overland Park, Kansas, an exceptionally wealthy Kansas-side suburb of Kansas City.
- Eric Stonestreet, one of the stars of Modern Family, is from Kansas City. He was the guest of honor at the illumination ceremony for the famous Country Club Plaza's Christmas lights. It's a big deal in KC.
- Oklahoma!: "Everything's up to date in Kansas City! They've gone about as fur as they can go..."
- Missouri native Robert A. Heinlein used Kansas City for the birthplace of Lazarus Long. The city itself is the backdrop for the last part of Time Enough for Love, in which Lazarus goes back in time to relive his childhood.
- Switched at Birth takes place here, which brings in Fridge Logic issues when the deaf school is shown to be part of the KCMO public school system while the main characters reside in Mission Hills, KS.
- The Pinkertons features a team of Pinkerton Detectives who work in Kansas City just after The American Civil War.
- Janelle Monáe is a KC native and occasionally mentions it in songs. ("Give me back my pyramid, I'm trying to free Kansas City.")
- Rapper Tech N9ne is from Kansas City and mentions it frequently.
- A Kansas City-based crime syndicate is an important faction in the second season of Fargo, and the city itself appears briefly in three episodes.
- The Day After takes place almost entirely in the Kansas City Metro, with most of the action happening in Lawrence and Kansas City itself.
- The third season of Queer Eye (2018) has the Fab Five making people over in and around Kansas City.
- Criminal Minds episode "Legacy" is set in Kansas. The fact that Kansas is in two different states is actual crucial plot point.