Keystone City is a city in the Smallville universe.
- Hex (Mentioned only) - Green Arrow mentioned Impulse and Clark dealing with a crisis in Keystone City.
- Haunted (Mentioned only) - Lois mentions Clark that in the over the past five years, "speed storms" have popped up in Keystone City,the ruins of LuthorCorp's abandoned Ridge Facility, Mexico, Miami, and islands in the Pacific Ocean, and have been increasing in frequency, causing people to superspeed aged to death. Clark immediately recognizes each as places Bart has been and that the storms are chasing him.
In the Comics
Keystone City is also home to Wally West (who is also known as The Flash), Max, Bart (who will later move to Los Angeles) and Jay Garrick (who is the original Flash). Within the comics, Keystone has been described as being "the blue collar capital of the United States" and a center of industry. Keystone City's location over the years has been treated as vague, much like DC's other fictional cities such as Gotham City and Metropolis, though most writers have shown it as being located in Pennsylvania (likely due to Pennsylvania being nicknamed "the Keystone State"). Starting in the 1990s, however, Keystone has been treated as being located in Kansas, near the Kansas/Missouri border, adjacent to Central City. Three miles from Keystone is Iron Heights, the security prison which holds the supervillains when captured.Besides heavy industry, Keystone is also the home of WKEY-TV, a television station where Wally's girlfriend/wife Linda Park works. Jakeem Williams (a.k.a. Jakeem Thunder of the JSA) attends Wilson High School in Keystone, according to JSA Classified #5. Barry Allen is one of the only people who is not located in Keystone instead he is located in Central City which is Keystone's twin city. The twin cities of Cental and Keystone have been nicknamed "the Gem Cities". Flash Vol 4 #7
- Along with Smallville, Metropolis, Gotham City, Hub City, Blüdhaven, Star City, Coast City, Central City and Themyscira, Keystone City is one of the confirmed DC Comics locales to be present in the world of Smallville.
- It is unknown if Jay Garrick defended Keystone in the show like he did in the comics.