- Vincent Martella (Phineas Flynn (voice))
- David Errigo Jr. (Ferb Fletcher (voice))
- Ashley French (Candace Flynn (voice))
- Caroline Rhea (Linda Flynn-Fletcher (voice))
- Dee Bradley Baker (Perry the Platypus (voice))
- Alyson Stoner (Isabella Garcia-Shapiro (voice))
- Dan Povenmire (Heinz Doofenshmirtz (voice))
- Jeff 'Swampy' Marsh (Francis Monogram (voice))
Phineas and Ferb — S3E1
Episode: The Great Indoors
Air Date: 2011-03-04
Runtime: 11 min
Overview
The third season begins with Phineas and Ferb building a gigantic biome during a bit of bad weather to help Isabella earn a Fireside Girl patch.