* Princess Bubblegum: The ruler of the Candy Kingdom and a brilliant scientist.
* Princess Bubblegum's Sister (formerly known as Princess Slime): Bubblegum's younger sister, who used to be a gooey slime monster.
There are also several other princesses, though they are not as prominent:
* Princess Bonnibel Bubblegum (Young): A younger version of Princess Bubblegum from flashbacks.
* Princess Cookie: A princess from a cookie-themed kingdom.
* Princess Slime Queen: A powerful Slime Princess.
* Princess Fifi: A princess known for her selfishness and vanity.
* Princess Hot Dog Girl: A princess with a hot dog head, who can control hot dogs.
* Princess Puffer: A princess who lives in a world of puffy, fluffy things.
* Princess Lolly: A princess who seems to be a human-like girl.
There are also other characters who are referred to as princesses but are not actually royalty, such as Flame Princess.