Fiona Flawless is the main antagonist of the Kidz Bop Comic Adventures series, starting on the sixth episode (and her debut episode). She is the head of the Flawless Five, consisting of herself and her four unnamed sisters. They live (and practice their singing) in a house with a dingy doorknob where neither of them ever remembers to take the trash cans in. They do a six-part harmony without a sixth member. While they are good singers and cookie bakers, they rub their talent into their opponents' faces (most specifically, the main character Amelia). In episode nine, she uses her cookies (with rainbow sprinkles) to manipulate Mr. Klump into wishing her luck (before he puts in the earplugs one of the Kidz Bop kids, Tammy, gave to him). After the Flawless Five have given the audience their talent and cookies, they bug Amelia and her band again. While they are performing, Fiona messes up the music and turns off the light, eventually getting Lucas blamed for it because he was the one asked to operate the lights from a lighting system made by another member named Eli.

When a wrongly blamed Lucas runs away and reward posters are put up, Fiona uses it to try to get money, and when Lucas is found, she and her sisters join people, such as Amelia's class and teacher, into following him back to Amelia's garage, where every member is watching the band in pleasure (except her).

While the voice actors are credited, it isn't said who voiced whom; therefore, it is unknown who voiced Fiona.