Olivia Rose Olson is an American singer and actress who voices Marceline in Adventure Time. She has also done voice acting on Phineas and Ferb as Vanessa Doofenshmirtz and The Powerpuff Girls as Bliss. Her adoptive father Martin Olson, who is also a screenwriter from Phineas and Ferb, voices Marceline's father Hunson Abadeer. She has posted videos of her singing on YouTube; her original songs include: "Sunny," "Loving You And Me," "Your Friend," "Sick 'n Tired," "Barriers," and "Suspicious." In 2018, Olivia Olson released her second album, Nowhere Land.
- Tom Kenny met Olivia when she was a baby because he was a comedy act at Martin Olson's club.