Rebecca Hanssen is a London-based actor of Norwegian and British nationality who has built a career across voice acting for animation and video games, as well as on-screen performances. Born on February 27, 1994, in Stavanger, Norway, she moved to Glasgow, Scotland at the age of four before relocating to London to pursue acting professionally. In animation, Hanssen is known for her role as Dorothy Brown in the series Love Through a Prism, where she voices the character of Lili's English friend and fellow painting student. She has also been cast as the lead in the upcoming Cartoon Network series Goat Girl, playing the character Gigi, and is attached to a major role in a forthcoming BBC anime feature film.

Hanssen's career in voice acting began in part through circumstances surrounding the COVID-19 pandemic, during which she recorded a voice demo in 2019 and signed with an agent, finding that voice work could continue from home when other productions shut down. Her first voice role was in the critically acclaimed game Baldur's Gate III, where she performed the character Alfira, a fan favorite bard, as well as additional roles including Yenna and Aurelia. She has also voiced the lead protagonist Eve in the action game Stellar Blade and Damiane in Crimson Desert. Her video game credits extend to a wide range of major titles. She voices Ch'en in Arknights: Endfield, and has performed roles in Wuthering Waves as the character Ciaccona, in The First Descendant as Luna, in Dying Light: The Beast as Olivia, in Lost Soul Aside as the Rose Queen, and in Eternal Strands as Casmyn. Other game credits include roles in Warhammer titles such as Blacktalon and Warhammer 40,000: Darktide, as well as Dragon's Quest III HD-2D Remake, Star Wars: Outlaws, and Dragon's Dogma 2. Beyond video games, she has voice roles in animated series including Warhammer: Blacktalon as Neave Blacktalon and the children's series Shasha and Milo as the title character Shasha and Vera. Her performance as Alfira in Baldur's Gate III and as Eve in Stellar Blade have been particularly recognized by audiences and within the industry.

In addition to voice acting, Hanssen appears on screen, most notably as Queen Meve of Lyria in Netflix's The Witcher, a role she played in the show's second and fourth seasons. She has also appeared in the series Blackshore, The Long Shadow as Pat Jackson, and the podcast series Sherlock & Co. as Maud Bellamy. Her film work includes roles in Enola Holmes, Tell It to the Bees as Irene, and Strange Creatures as Emma Cormack. Hanssen has received motion capture training with Pitstop Productions and has approximately four years of experience in motion capture performance, particularly from her work on Baldur's Gate III from 2019 to 2023. She maintains a home studio in Northwest London equipped with a Shure SM7B microphone and Logic Pro software, and she is skilled in performing a variety of accents including her native Scottish, a neutral English accent, American English, and Norwegian. Her professional representation is through Gung Ho Bookings and Damn Good Voices.