Holly (voiced by Cymphonique Miller) is one of the Fireside Girls in Danville Troop 46231.
Candace tried to get one of several items from her in order to bust Phineas and Ferb during the Brawl at the Mall. She also got seasick while singing The Ballad of Badbeard. ("Raging Bully", "The Ballad of Badbeard") She along with Ginger, Milly, and Katie help Phineas and Ferb create S'winter ("S'Winter").
She and Katie also participated in the Chariot Race with Isabella ("Greece Lightning"). Her hairstyle was also different in that it consisted of two straight pigtails as opposed to the usual puffy pigtails she has. She also asks Phineas how they're going to defeat the gelatin monster ("Day of the Living Gelatin").
When the Fireside Girls were trying to raise money to save the Star-nosed Mole, she somehow got hurt during the Fireside Girls' attempt at a bake sale ("At the Car Wash"). She walked on backs with Ginger and Isabella when Phineas and Ferb built a Spa ("Spa Day").
Holly is a short, slender, dark-skinned girl with jet-black hair in two puffy pigtails tied with yellow hairbands and brown eyes. Her Fireside Girl uniform has a red collar with a dent in the middle and two small splits at the sides of her sleeves, with sneakers with a strap going all the way across. In some appearances, Holly has two small buck teeth. However, in other appearances, the teeth are not visible. In winter, she switches to an orange sweater with an off-white collar and red zigzags, and red boots.
- Help Thy Neighbor Patch (About 52 as of "Isabella and the Temple of Sap")
- Aquatic Safety Patch
- Sewing Patch
- Tent Pitching Patch, Marshmallow Patch
- Aeronautic Patch
- Broadcasting Patch (possible)
- Shrimp Net Repair Patch
- Sap Collecting Patch
- Mountain Moving Patch
- Rodeo Clown Patch
- Desert Tracking Patch
- Rain-forest/Jungle Navigation Patch
- Rock-climbing Patch
- Non-power Flight Patch
- Concussion First-aid Patch
- Her first speaking role was the episode "Raging Bully", as she tells Candace that there are no souvenirs for the brawl left.
- In "It's About Time!", Holly is seen without her beret in one scene when the girls are looking at a message Phineas and Ferb left from 300 million B.C.
- She was the only Fireside Girl (other than Isabella) who appeared in "Comet Kermillian" and in a flashback in "My Fair Goalie".
- Her name was mentioned on-screen for the first time (along with the other Fireside Girls' names) by the supercomputer Phineas and Ferb built in "Ask a Foolish Question".
Actress Cymphonique Miller was listed in the credits of "Raging Bully" as Holly. However, she was not the only speaking Fireside Girl in that episode. Milly (the curly brown-haired Fireside Girl) also speaks during the episode as she passes out the fliers to the patrons at Googolplex Mall, while Holly and Ginger are pestered by Candace to try and get something to bring to Linda in order to prove to her that Phineas and Buford are fighting. It is unclear from this episode alone which Fireside Girl is Holly.
The proof comes several episodes later in "The Ballad of Badbeard". Cymphonique is credited again, this time as an additional voice, as is Ariel Winter who plays Gretchen. Since we know who Gretchen is, and the only other female voice heard comes from Holly who is seasick on Phineas and Ferb's ship along with Gretchen.