Caroline in the City crossed over with both Frasier and Friends, tying the universes together.
Munch also connects it to the X-Files universe, The Beat, Arrested Development, and The Wire.
Ties into the Disney Channel sitcom universe through Girl Meets World.
Adjacent Series: Batman (1966), Batman (1989 film), Smallville, Birds of Prey (TV Series), Constantine (TV series), The Flash (1990 TV series), Superman Returns, Green Lantern (2011), Lucifer, Titans, Doom Patrol, Stargirl, DC Extended Universe, and Swamp Thing Big Time Rush also connects it to Yo Gabba Gabba!, How to Rock, and Marvin Marvin.
This is a partial list of fictional universes created for both television and cinema.