Every Fireside Girls has participated in several of Phineas and Ferb's Big Ideas, with Isabella being the most common and sometimes helps her on occasions. However, in "I Was a Middle Aged Robot" onwards, two new Fireside Girls appeared as well as the addition of the Lil' Sparks, and except for "Ask a Foolish Question" that they were only mentioned.
Participation in the Big Ideas[]
| Episode | Participation | Participating Fireside Girls |
| "Rollercoaster" | Watched the unveiling of Phineas and Ferb's Rollercoaster. | Katie and Ginger |
| "Lawn Gnome Beach Party of Terror" | Helped as lifeguards at the backyard beach. | Ginger, Katie, Milly, Holly, Gretchen and Adyson |
| "Flop Starz" | Sung in the band Phineas and the Ferb-Tones, in a group called The Ferbettes. | Gretchen, Adyson and Milly |
| "The Fast and the Phineas" | Acted as Phineas's pit crew. | Katie, Adyson, Holly, Gretchen, Ginger, Milly |
| "Lights, Candace, Action!" | Helped on the movie set. | Holly, Gretchen, Milly, and Ginger |
| "Raging Bully" | Helped the ring's construction and gave out fliers of the brawl. | Milly, Ginger, Holly, Katie, Adyson and Gretchen |
| "Candace Loses Her Head" | Distracted Candace from seeing her present. | Ginger, Milly, Holly, Gretchen, Katie and Adyson |
| "Run Away Runway" | Helped create the Summer All The Time Collection. | Holly, Milly, Ginger, Adyson and Katie |
| "S'Winter" | Helped to create and sang S'Winter. | Milly, Katie, Ginger, Holly, Adyson and Gretchen |
| "Jerk De Soleil" | Participated in the show as acrobatic performers. | Katie, Ginger, Gretchen, Holly, Milly, Adyson and plus other unofficial Fireside Girls |
| "Get That Bigfoot Outa My Face!" | Went to Camp Phineas and Ferb to earn various accomplishment patches. | Gretchen, Milly, Holly, Adyson, Ginger and Katie |
| "Mom's Birthday" | Helped with the festivities and sang background vocals on I Love You Mom. | Milly, Adyson, Gretchen, Holly, Ginger and Katie |
| "It's About Time!" | Built a new time machine to rescue Candace and the boys from prehistoric times. | Ginger, Gretchen, Adyson, Milly, Holly and Katie |
| "Dude, We're Getting the Band Back Together" | Built the stage for Love Händel's performance and became backup dancers. | Gretchen, Katie, Holly, Ginger, Adyson and Milly |
| "Tree to Get Ready" | Witnessed the tree house fight. | Milly, Katie, Ginger Hirano, Holly, Adyson and Gretchen |
| "The Ballad of Badbeard" | Assisted in the search for Badbeard's Treasure on Spleen Island. | Holly, Gretchen, Ginger, Adyson and Milly |
| "Greece Lightning" | Rode in the chariot race and witnessed it. | Holly, Katie and Ginger |
| "Leave the Busting to Us!" | Went on the Ferris wheel and water slide. | Holly and Ginger |
| "Comet Kermillian" | Watched the comet in the observatory. | Holly only |
| "Put That Putter Away" | Built and played on Phineas and Ferb's mini-golf course, and dancers during the Disco Miniature Golfing Queen song. | Gretchen, Ginger, Adyson and Holly |
| "The Flying Fishmonger" | Helped sing the original song and the new, improved song. | Gretchen, Milly, Katie, Adyson and Holly |
| "One Good Scare Ought to Do It!" | Constructed the Haunted House and dressed up in monster costumes to scare away Isabella's hiccups. Also saved Phineas's life when he fell. | Gretchen, Adyson, Katie, Milly, Ginger and Holly |
| "Out of Toon" | Helped on the making of the giant TV and the Phineas & Ferb Studios. | Milly, Katie, Adyson and Ginger |
| "Out to Launch" | Worked in the space port to monitor the boys' launch. | Ginger, Adyson, Holly, Katie, Milly, and Gretchen |
| "Interview With a Platypus" | Helped by interviewing the talking animals. | Milly, Adyson and Ginger |
| "Tip of the Day" | Helped spread the awareness of aglets and sung in the Aglet-Aid concert. | Milly, Katie, Ginger, Holly, Adyson and Gretchen |
| "Day of the Living Gelatin" | Helped Phineas and Ferb mix the ingredients for the giant gelatin and later defeated it. | Milly, Katie, Ginger, Adyson, Holly and Gretchen |
| "Don't Even Blink" | Helped on finding where the projects Phineas and Ferb's creations disappear to. | Milly, Katie, Gretchen, Ginger, Holly and Adyson |
| "Chez Platypus" | Cooked and served delicious foods at Chez Platypus. | Gretchen, Ginger Hirano, Katie, Adyson, Milly and Holly |
| "Thaddeus and Thor" | Witnessed and the unveiling of the fort. | Gretchen, Ginger, Holly, Adyson, Milly and Katie |
| "De Plane! De Plane!" | They helped Phineas and Ferb break the world record for biggest airplane in the world and appear as backup dancers for "Big Ginormous Airplane". | Gretchen, Adyson, Katie, Holly, Ginger and Milly |
| "Let's Take a Quiz | They helped Phineas and Ferb organize their show to earn their Broadcasting patches. | Gretchen, Holly and Ginger |
| "At the Car Wash" | Ran the car wash so they can save the Starnose Mole. | Holly, Ginger, Katie, Gretchen, Adyson and Milly |
| "Oh, There You Are, Perry" | Helped sing Come Home Perry. | Milly, Katie, Ginger, Holly, Adyson and Gretchen |
| "That Sinking Feeling" | Rode along in the ocean cruise ship. | Gretchen, Ginger, Adyson, and Holly |
| "Spa Day" | Helped the boys in the Spa and sang in Spa Day. | Holly, Milly, Ginger, Katie and Gretchen |
| "Phineas and Ferb Musical Cliptastic Countdown" | Sang "Gitchee Gitchee Goo" Extended version. | Gretchen, Adyson and Milly |
| "Bubble Boys" | Went in the bubble with Phineas and the boys. | Gretchen, Katie, Ginger, Milly, Adyson and Holly |
| "Isabella and the Temple of Sap" | Went to retrieve the sap from the Maracanut Tree for Phineas and Ferb. | Ginger, Holly, Katie, Gretchen, Milly and Adyson |
| "Cheer Up Candace" | Attended Phineas and Ferb's Comedy Club. | Holly, Ginger and Milly |
| "Fireside Girl Jamboree" | Helped Candace become a member of the Fireside Girls. | Holly, Ginger, Adyson, Katie, Gretchen, Milly, and Candace Flynn |
| "What Do It Do?" | Helped Phineas and Ferb find out what the robot does. | Katie and Holly |
| "Phineas and Ferb Christmas Vacation!" | Danced during the Ending Credits. | Katie, Holly, Milly, Ginger and Adyson Sweetwater |
| "Candace's Big Day" | Helped the boys with Tiana and Bob's wedding. | Milly, Holly, Ginger, Adyson, Katie, and Gretchen |
| "I Was a Middle Aged Robot" | Helped Cheer for Lawrence and Candace. | Adyson, Ginger Hirano, Katie, Holly, Gretchen, Milly and plus two new Fireside Girls: Fireside Girl (blond) and Fireside Girl (brunette) |
| "Hip Hip Parade" | Went along in the Parade. | Ginger Hirano and Holly |
| "Robot Rodeo" | Acted as Rodeo Clowns in the Rodeo. | Adyson Sweetwater, Gretchen, and Holly |
| "The Beak" | Delivered the Fireside Girls Gazette in the neighborhood. | Fireside Girl (blond) only |
| "The Lemonade Stand" | Helped franchise and sells P&F Lemonade. | Ginger Hirano, Milly, Adyson, Gretchen, and Holly |
| "Phineas and Ferb: Summer Belongs to You!" | Watched the Amazing Sun Beater-3000 leaves and prepared a party for their return. They also danced to the Summer Belongs to You song. | Milly, Adyson, Gretchen, Holly, Ginger, Katie, and Fireside Girl (blond) |
| "We Call it Maze" | Joined with Isabella and Candace in the Maze. | A Lil' Spark: Melissa |
| "Wizard of Odd" | Seen as Patchkins and sings The Yellow Sidewalk. | Gretchen, Fireside Girl (blond), Adyson, Holly, Ginger, Milly, Katie, and a Dream Fireside Girl |
| "Rollercoaster: The Musical!" | Sang in What'cha Doin'?. Also rode along in the roller-coaster. Finally, participated in Carpe Diem. | Katie, Ginger, Milly, Gretchen, Holly and Adyson |
| "The Great Indoors" | Went inside the biosphere to earn their patches. | Holly, Ginger, Katie, Milly, Gretchen and Adyson |
| "Phineas' Birthday Clip-O-Rama!" | Re-enacted a parody of "Howl" and greeted Phineas for his birthday. | Holly, Gretchen, Ginger, Milly, Katie and Adyson |
| Phineas and Ferb the Movie: Across the 2nd Dimension | Participated in the battle against the 2nd dimension Doofenshmirtz and his robot army. Also, they had their memories of that day erased later on. | Adyson, Milly, Holly, Katie, Gretchen, Ginger, and many other Fireside Girls. |
| "Tour de Ferb" | Helped out in the bike race. | Milly, Katie, Ginger, Holly, Gretchen, Adyson and a new Fireside Girl: Fireside Girl (brown) |
| "A Phineas and Ferb Family Christmas | Sang in Let it Snow, Let it Snow, Let it Snow. They also hung out in Phineas and Ferb's log cabin. | Milly, Ginger, Katie, Gretchen, Adyson and Holly |
| "Tri-Stone Area" | Seen as cave-girls and sang Zubada. | Adyson Sweetwater, Holly, Milly, Katie, Ginger and Gretchen |
| "Excaliferb" | Summoned by Isabel as water sprites and help save Phineas, Ferbalot and their friends. | Milly, Katie, Ginger, Holly, Adyson and Gretchen |
| "Monster from the Id" | Went into Candace's sub-conciseness. | Holly, Ginger, Gretchen, Katie and Milly |
| "The Remains of the Platypus" | Helped spread fliers for Cheesetopia. | Gretchen, Adyson, Milly, Ginger, Katie and Holly |
| "Buford Confidential" | Helped Isabella capture the American Grizzly Bear. | New Fireside Girls: Brigitte, Josette and Collette |
| "What A Croc!" | Helped chased Crikey the Crocodile and Candace via jet-ski. | Gretchen, Holly and Milly |
| "Agent Doof" | Seen taken care of the babies in the baby shower party. | Ginger, Adyson, Milly, Gretchen and Katie |
| "Sleepwalk Surprise" | Seen playing Jetpack Volleyball. | Milly, Katie, Gretchen and Ginger |
| "Sipping with the Enemy" | Helped build the magic show and became backup dancers. | Katie, Ginger, Gretchen Milly, Adyson, Holly and Fireside Girl (blond) |
| "Ferb TV" | Seen them doing their own commercial in a military-style theme. | Ginger, Adyson, Holly, Katie, Gretchen, Milly and many other Fireside Girls. |
| "Happy New Year!" | Seen looking the New Year's Ball, rode and dancing in it. | Adyson, Ginger, Holly, Gretchen, Milly and Katie |
| "Backyard Hodge Podge" | Seen having fun in the Hodge Podge. | Ginger Hirano, Gretchen and Katie |
| "Bee Day" and "Bee Story" | Went to Phineas and Ferb's wading pool party. | Gretchen and Holly |
| "Great Balls Of Water" | Went swimming in the worlds largest ball of water. | Ginger, Katie, Adyson Sweetwater, Holly, Gretchen, Milly and Melissa |
| "Happy Birthday, Isabella" | Helped make Isabella's Birthday party. | Gretchen Adyson, Holly, Katie, Milly, Ginger and Melissa |
| "Love at First Byte" | Helped distribute safety glasses for the grand finale. | Gretchen, Milly, Ginger, Adyson, Katie and Holly |
| "One Good Turn" | Participated in the Phineas and Ferb obstacle course. | Ginger Hirano only |
| "Thanks But No Thanks" | Seen doing the pyramid. | Holly, Milly, Katie, Adyson, Ginger and Gretchen |
| "Troy Story" | Seen defense the Troy wall replica. | Adyson, Ginger, Milly, Holly and Gretchen |
| "Return Policy" | Seen playing extreme batting. | Gretchen and Ginger |
| "The Return of the Rogue Rabbit" | Helped controlled the giant marionette. | Gretchen, Ginger, Milly, Katie, Holly and Adyson |
| "It's No Picnic" | Helped Isabella sets a romantic picnic and seen riding in the picnic amusement park. | Gretchen, Ginger, Holly, Katie, Milly and Adyson |
| "Operation Crumb Cake" | Helped Isabella to get the love letter that she accidentally sent. | Gretchen, Holly, Adyson, Ginger, Milly and Katie |
| "Act Your Age" | Along with Ferb, Baljeet, and Buford, they tried to make a romantic dinner for Phineas and Isabella. | Holly, Ginger, Katie, Milly, Gretchen, and Adyson |