|Full Name||Katie Persky|
|Friends||Allie, Corey Riffin, Laney Penn, Kin Kujira, Kon Kujira, Trina Riffin (mixed)|
|Enemies||Trina Riffin (mixed)|
|Love Interest||Nick Mallory (Wicked Cool Transition Builder only), Corey Riffin|
|First Appearance||Grojband Pilot|
|Latest Appearance||Curse of the Metrognome (Cameo)|
|Voice Actor||Madelyn May|
Katie "Kate" Persky is one of Grojband's adorable groupies. She is the biggest fan of Grojband along with her best friend, Allie. She is a pretty brown haired girl that has a crazy obsession for Grojband and usually squeals over Grojband and is in love with every single member of the band mostly Corey.
Kate is a 9-year-old girl with short brunette with her hair in a curly bun and glasses. Her skin has many freckles and her shirt is white with black sleeves and fire on it which matches the shirt that Kon wears. She also wear teal pants and red sneakers.
Kate is a Grojband obsessed fan girl who will risk her life to help out with the band.
- Cloudy with a Chance of Malt Balls
- Indie Road Rager
- Hair Today, Kon Tomorrow
- Girl Fest
- The Bandidate
- Group Hug
- Grojband Pilot
- Smash Up Terby
- Dance of the Dead
- Math of Kon (Cameo)
- Space Jammin' (Non-Speaking Cameo)
- Monster of Rock
- One Plant Band (Non-Speaking Cameo)
- The Pirate Lounge for Me
- Who Are You (Cameo)
- A-Capella-Lips Now (Non-Speaking Cameo)
- That's My Jam (Cameo)
- It's in the Card
- Curse of the Metrognome (Non-Speaking Cameo)
- Although Kate and Allie are the biggest fans of Grojband, they have been shown to be huge fans of others celebrities in the show.
- In the episode Group Hug, Corey revealed to her and Allie that he doesn't write his owen lyrics and that he steals them from Trina's diary. This makes her, Allie, and The Orb Experience are the only ones who know this secret about his band.