Marika Hayashi is a Japanese actress and voice actress born on April 17, 1975, in Kanagawa Prefecture. She has been active in the entertainment industry since 1998 and is the daughter of actor Ryuzo Hayashi. Her career encompasses a wide range of voice work in anime television series, video games, and Japanese dubs of foreign live-action and animated films.

In anime, Hayashi has portrayed a variety of characters across different series. She is recognized for her role as the skilled and pragmatic swordswoman Hyakurin in the 2019 anime adaptation of Blade of the Immortal. Her other anime credits include Adette Kistler in Overman King Gainer, Miss Rose in Kino's Journey, Panyi in Tatakau Shisho, and Michiru in Darker than Black: Ryūsei no Gemini. She also voiced the character Amayo in a Naruto film and the Capricorn's Star Princess in Star Twinkle PreCure. Additional anime roles include appearances in Violet Evergarden, Night Raid 1931, and The Wings of Rean.

Hayashi has also contributed her voice to animated films and original net animations. Notably, she voiced the hunter Nadia in the 2021 Netflix CG-animated film Monster Hunter: Legends of the Guild. She also had a role in the 2018 film Anemone: Eureka Seven Hi-Evolution.

Her work in video games is extensive. She is known for providing the Japanese voice of Annette Birkin in the 2019 remake of Resident Evil 2 and its 2020 sequel Resident Evil 3. Other prominent game roles include Vijounne in The Wonderful 101 and Lina Navarro in Need for Speed Payback. She also voiced a character in the 2023 game Starfield.

A significant portion of Hayashi's career is dedicated to dubbing, providing Japanese voices for numerous international actors and characters. She is a frequent dubbing voice for actresses such as Kate Winslet, Morena Baccarin, and Rosamund Pike. Her dubbing credits include Clementine Kruczynski for Kate Winslet in Eternal Sunshine of the Spotless Mind, Vanessa for Morena Baccarin in the Deadpool films, and Helen Rodin for Rosamund Pike in Jack Reacher. Other notable dubbing roles include Agent 99 for Anne Hathaway in Get Smart, Chloe O'Brian for Mary Lynn Rajskub in 24, and Dejah Thoris for Lynn Collins in John Carter. She has also dubbed voices in numerous other films and television series, such as ER, Grey's Anatomy, Criminal Minds, and Transformers.

Through her diverse body of work in animation, video games, and dubbing, Marika Hayashi has established herself as a versatile and prominent figure in the Japanese voice acting industry.