Olivia Rose Olson credited as Olivia Olson was born and raised in Los Angeles, California, and lives with her mother, brother and father, Phineas and Ferb writer and songwriter Martin Olson. She has appeared as a singer and actress on many television shows and has performed live in many Hollywood theaters, including The Comedy Central Stage, The HBO Theater and The Fake Gallery.
She is currently a semi-regular cast member of Disney's animated series Phineas and Ferb and voices Vanessa, the sarcastic daughter of Dr. Doofenshmirtz. She also sings many of the songs in this Disney series, including a catchy duet called Busted with co-star Ashley Tisdale. She has also sung songs as other characters, such as I'm Lindana and I Wanna Have Fun! as Linda Flynn-Fletcher. She also provides the guide track vocals for Candace's songs.
She has written songs for Phineas and Ferb, has written and recorded her songs with renowned music producers Rick Nowels, Camara Kambon and Hollywood jazz great Rob Mullins, and for fun performs many of her original songs in YouTube videos: Sunny, Loving You And Me, Your Friend, Suspicious, and Sick N Tired. Her new extended play album, Beauty is Chaos is available on iTunes now. 
At age ten, Olivia appeared in the British film Love Actually with fellow Phineas and Ferb voice actor Thomas Sangster, singing the song "All I Want for Christmas is You". According to director Richard Curtis' commentary in the Love Actually DVD, Olivia's singing was so perfect, they were afraid the audience would not believe that a ten-year-old could really sing the way she did. They had to train her so that her singing would sound more believable.
Olivia also voices the popular character Marceline the Vampire Queen in the cartoon Adventure Time.
Songs in Phineas and Ferb
As Vanessa Doofenshmirtz
- Busted (with Candace Flynn)
- I'm Me
- Not So Bad A Dad
- The Twelve Days of Christmas
- The Christmas Song (Chestnuts Roasting on an Open Fire)
- Lookin' for Books
- Vanessa's Song
- Ducky Momo Theme Song
- I'm Feelin' So Low
- Rebel, Let's Go!
As Olivia Olson
- He's Eviler (chorus)
- That Christmas Feeling
- Moon Farm (with Dan Povenmire)
- Real Boy (chorus)
- I Walk Away
- Happy New Year
As Other characters
- Olivia Olson at Wikipedia
- Olivia Olson at
- YouTube channel
- Olivia Olson - Video Excerpts
- "Not So Bad a Dad" by Olivia Olson
- "Busted" by Olivia Olson and Ashley Tisdale
- Mom It's Your Birthday Demo sung by Olivia Olson