Cerulean City/Anime/Main series

Cerulean City first appeared in The Water Flowers of Cerulean City, where decided to challenge the Cerulean Gym. At the Gym, he found out that and the other two Trainers from Pallet Town had already beaten the Gym. As their only remaining Pokémon after those challengers was a, the Sensational Sisters were ready to give Ash the without a , until  appeared, revealing herself to be one of the Cerulean Gym Leaders as well. Ash and Misty started a Gym battle, but just when Ash was about to win, busted their way into Gym, interrupting the battle. After Team Rocket had been defeated, the Sensational Sisters decided to give Ash the Cascade Badge as thanks for saving the Gym.

Cerulean City made a reappearance in The Misty Mermaid, where Misty reluctantly agreed to help her sisters in a new underwater ballet performance. However, in the middle of the act, Team Rocket appeared again, once more trying to steal the Gym's Pokémon. A battle between Ash and company and Team Rocket ensued, during which Cerulean Gym's evolved into a. Once the situation was solved and Ash and company prepared to leave, Misty left her and  at the Gym, the latter due to her sisters' request.

Cerulean City was also featured in the Pokémon Chronicles episodes Cerulean Blues, The Blue Badge of Courage, A Date With Delcatty, and Luvdisc is a Many Splendored Thing!, which mostly focused on the Cerulean Gym and Misty. In A Date With Delcatty, Cerulean City was revealed to have a container port, the Cerulean Marine Stadium, and a lighthouse.

Ash,, Misty, , and Professor Kukui visited Cerulean City in Alola, Kanto! and When Regions Collide! to visit the Cerulean Gym and teach Ash's Alolan friends about Gyms and Pokémon Leagues. To experience a Gym battle, and  had an unofficial Gym battle against Brock, while  and  had a battle against Misty. After these battles had been called off with no clear winner, requested to have a serious battle against Brock, while Ash issued a similar challenge to Misty. During these battles, Brock and Misty demonstrated their new ability to use Mega Evolution by Mega Evolving their and, respectively. Kiawe lost his battle against Brock, while Ash managed to defeat Misty.

The is also located near Cerulean City.