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.
2026Adventure Time: Side QuestsTV showas Marceline (voice) · 20 episodes2025Teller's CampMovieas Sadie O'Leary2023Adventure Time: Fionna and CakeTV showas Marceline / Celine (voice) · as Marceline (voice) · 6 episodes2022The Laughter & Secrets of Love Actually: 20 Years Later – A Diane Sawyer SpecialMovieas Self2022We Baby BearsTV showas Ursa (voice) · as Pegasus / Employee / Goblin (voice) · as Ursa / Young Cassi (voice) · as Ursa / Voice on TV (voice) · as Pegasus (voice) · 2 episodes2020The GloriasMovieas Susanne Steinem (uncredited)
2020GrapefruitMovieas Grapefruit2020Adventure Time: Distant LandsTV showas Marceline the Vampire Queen / Additional Voices (voice) · 1 episodes2020Phineas and Ferb the Movie: Candace Against the UniverseMovieas Vanessa Doofenshmirtz (voice)2019Fast & Furious Spy RacersTV showas PizzaRave (voice) · as Jun · as Guard (voice) · as Jun (voice) · as PizzaRave / Jun (voice) · 3 episodes2017Red Nose Day ActuallyMovieas Joanna2016The Powerpuff GirlsTV showas Bliss (voice) · 6 episodes2015Adventure Time - Mini Series “Stakes!”TV showas Marceline the Vampire Queen · 8 episodes2014Phineas and Ferb: Star WarsMovieas Vanessa the Twi'Lek (voice)2013Steven UniverseTV showas Pop Singer (voice) · 1 episodes
2012Adventure Time: Fun with Finn and JakeMovieas Marceline the Vampire Queen (voice)
2012Voice OverMovieas Little Girl
2011Inanimate InsanityTV showLyricist · Songs · 1 episodes2010Adventure TimeTV showas Marceline the Vampire Queen (voice) · 279 episodes2010Phineas and Ferb Summer Belongs to you !Movieas Vanessa Doofenshmirtz