Olivia Olson

Olivia Rose Olson (born May 21, 1992) is an American actress, singer-songwriter, and writer. She is best known for her voice roles as Vanessa Doofenshmirtz in Phineas and Ferb and Marceline the Vampire Queen in Adventure Time. Olson also played the character of Joanna in the 2003 film Love Actually and its 2017 short sequel Red Nose Day Actually. Additionally, she is a writer, having penned the Boom! Studios graphic novel Marcy and Simon, co-authored Adventure Time: The Enchiridion and Marcy's Super-Secret Scrapbook, and contributed to the Adventure Time Encyclopedia. Olson was adopted at birth and raised in Los Angeles, California. She is of Afro-Jamaican descent through her biological father.