Polly Pocket - An 11-year-old kid genius with a thirst for adventure, and wants to help people. She inherits her locket from her grandmother Penelope Pocket.
Lila Draper - Polly's fashion savvy friend who often exclaims using fashion terms and pieces. She loves fashion, and finds that shrinking can be chic. It is hinted at the end of episode 11 that she might be developing feelings for Nicholas Wells despite their initial dislike of each other.
Shani - A science fiction nerd who formerly had stage fright, Shani serves as the peacekeeper and brains of the group. Her favorite show is "Y-Girls" and she is a follower of Nicholas' vlog.
GenI - An A.I. program created by Polly to interact with her tech.
Recurring
Penelope Pocket - Polly's grandma and the previous bearer of the Pocket Locket.
Pierce Pocket - Polly's 16-year-old brother. It is revealed he does karate in episode 6, and that he works for store owner Peanut as delivery boy-turned-assistant manager in episode 10.
Mrs. Pocket - Polly's mother.
Mr. Pocket - Polly's father.
Paxton Pocket - Polly's baby brother and the only one of Polly's relatives, other than Grandma Penelope, that knows Polly's secret.
Peaches Pocket - Polly's pet dog.
Nicholas Wells - A boy in Polly's class who attempts to investigate the paranormal. In the mid-season finale, he discovers the girls' secret, but in episode 11, he becomes the posse's fourth member when he helps them thwart Griselle's plot to be mayor and take over the town and promising to keep the girls' secret safe.
Melody - A teenage pop singer who becomes the girls' ally in episode 2 when she is rescued by Polly via her locket.
Peanut - A restaurant owner who is known for making cupcakes. Pierce Pocket works for him as his delivery boy, and later assistant manager in episode 11.
Tori - Shani's older cousin.
Melissa Militant - A strict girl scout troop leader who does things in a military boot camp fashion.
Principal Mondo - The elementary school's quirky, eccentric but fairly strict principal.
Villains
Griselle Grande - A 60-year-old and vain woman, she was Penelope Pocket's college roommate who discovered the Pocket Locket's abilities when Penelope dropped a small environmental suit from one of her adventures, and tried to take it from her. The two fought but broke the locket, making Griselle lose it after the two went their separate ways. She spent years using her science to replicate its powers but failed, until the day when she discovered Polly Pocket had found it and reactivated its powers. She and Gwen now try to take the locket to conquer Littleton by shrinking its citizens and trapping them in a model city called "Grandeville". She eventually gets arrested at the end of episode 13, after her plan to become the town's new mayor, steal Polly's locket, and shrink the Littleton while covering it in an energy bubble failed, and Nicholas helped Lila and Shani expose Griselle's secret plans to the world. But after doing community service, she resumes her hunt for the locket while also wanting revenge on Polly and her friends, starting with episode 15 onwards.
Gwen Grande - Griselle Grande's dim-witted granddaughter and Polly's rival inside and outside of school. In episode 7, "Con Job", she actually helps the girls escape to avoid Griselle ruining their one day off from Pocket-hunting.
Paranormal Patty - A paranormal investigator whose only appearance so far is in "Pocket Poltergeist" when Pierce, believing to have been haunted by a ghost calls her in, unaware it was the Pocket Posse pulling a prank. Aside from her equipment almost ratting out Polly's secret, she tried to destroy the Pocket house in an attempt to get rid of the ghost before Polly arranged for her and Pierce to "banish" it,, with a spirit dance.
Mr. Scheeman - A shady businessman who conned Nicholas into journeying to Almost Dead-Man's Island, hoping the boy's vlog would spread rumors about a haunted temple and keep competing businesses from taking root there. His magnet crane caused Polly's powers to glitch until Shani found and disabled it. He stole a sample of genuine "Bigfoot" hair from Nick until Shani stole it back in secret.
