Olivia Rose Olson (born May 21, 1992) is an American actress and singer-songwriter, mostly known for her voice roles as Vanessa Doofenshmirtz in Phineas and Ferb and Marceline the Vampire Queen in Adventure Time. She also played the character of Joanna in the 2003 film Love Actually and its 2017 short sequel Red Nose Day Actually.

Filmography

• Adventure Time: Side Quests — Marceline (voice)
• 2025Teller's Camp — Sadie O'Leary
• Adventure Time: Fionna and Cake — Marceline / Celine (voice), Marceline (voice)
• We Baby Bears — Ursa (voice), Pegasus / Employee / Goblin (voice), Ursa / Young Cassi (voice), Ursa / Voice on TV (voice), Pegasus (voice)
• Adventure Time: Distant Lands — Marceline the Vampire Queen / Additional Voices (voice)
• 2020Grapefruit — Grapefruit
• 2020Phineas and Ferb the Movie: Candace Against the Universe — Vanessa Doofenshmirtz (voice)
• 2020The Glorias — Susanne Steinem (uncredited)
• Fast & Furious Spy Racers — PizzaRave (voice), Jun, Guard (voice), Jun (voice), PizzaRave / Jun (voice)
• 2017Red Nose Day Actually — Joanna
• The Powerpuff Girls — Bliss (voice)
• 2014Phineas and Ferb: Star Wars — Vanessa the Twi'Lek (voice)
• Steven Universe — Pop Singer (voice)
• 2012Adventure Time: Fun with Finn and Jake — Marceline the Vampire Queen (voice)
• 2012Voice Over — Little Girl
• Inanimate Insanity — Lyricist, Songs
• Adventure Time — Marceline the Vampire Queen (voice)
• Phineas and Ferb — Vennesa the Twi'Lek (voice), Vanessa (voice), Writer, Story
• Zoey 101 — Girl #1
• 2003Love Actually — Joanna Anderson
• The Tracy Morgan Show — Julia

Appearances as themselves (1)

• 2022The Laughter & Secrets of Love Actually: 20 Years Later – A Diane Sawyer Special — Self