Karen Strassman is an American actress who has built an extensive career providing English voices for Japanese anime series, video games, and animated productions. Born in Washington, D.C., she developed an interest in acting from a young age and moved to France when she was twenty to study psychology and theatre at the Conservatoire national supérieur d'art dramatique (CNSAD) in Paris. This period in France proved foundational for her voice-acting career. While there, she responded to an advertisement seeking English-speaking actors, leading to an apprenticeship and later a paid position as a dialect coach, where she trained French actors in English. She also began doing voice-over work for a children's magazine, which was her entry into the field. Strassman is a naturalized French citizen and is fluent in the language, a skill that has allowed her to perform voice-over work in French for clients such as Air France, Disneyland Paris, and audio tours for the Louvre museum.

Strassman's anime voice-over career is marked by a wide range of roles across numerous popular and long-running series. She is perhaps best known for her portrayal of Kallen Stadtfeld (also known as Kallen Kozuki) in the acclaimed mecha series Code Geass: Lelouch of the Rebellion and its sequel, Code Geass: Lelouch of the Rebellion R2, a role she reprised for the film Code Geass: Lelouch of the Re;surrection. Another significant and long-running role is in the series Bleach, where she voices both Captain Soi Fon and Lieutenant Momo Hinamori. Her versatility is further demonstrated by roles such as the gentle Miyuki Takara in Lucky Star, the complex Nina Fortner in the psychological thriller Monster, the cool and mysterious Rider in Fate/stay night, and the music teacher Sawako Yamanaka in K-On!. She also voiced the young Casval Rem Deikun, the boy who would become Char Aznable, in Mobile Suit Gundam: The Origin.

In addition to these prominent roles, Strassman has contributed her voice to a vast number of other anime, often taking on multiple characters within a single series. Examples include her role as the homeroom teacher Kazuko Saotome in Puella Magi Madoka Magica, Sumi Ikuina in Ah My Buddha, and her dual roles as Natsuki and Reika Fou in the OVA series Dangaizer 3. Her film work includes voicing Kanako Azumi in the theatrical film Children of the Sea and providing the narration for the educational yet action-packed series Cells at Work!. She also voiced the character Genovan in the CGI film Monster Hunter: Legends of the Guild. Her filmography also includes the role of Rowell Su-ming in Flag, Yasuna Kamiizumi in Kashimashi: Girl Meets Girl, Yuki the Snake in Angel Tales, Muginami in Lagrange: The Flower of Rin-ne, and Liala in The Testament of Sister New Devil BURST.

Throughout her career, Strassman has been a consistent presence in anime produced during the 2000s and 2010s, often working on projects dubbed by major studios in Los Angeles. Her body of work reveals a recurring pattern of being cast in prominent supporting roles, particularly those requiring a range of emotions, from the fierce determination of a mecha pilot to the quiet warmth of a maternal figure. Her ability to portray characters with distinct personalities has made her a familiar and respected voice in the industry. While primarily known for her anime work, her career also encompasses a significant number of roles in Western animation and video games, most notably as the voice of Rouge the Bat in the Sonic the Hedgehog franchise.