Chiwa Saitō is a Japanese voice actress born on March 12, 1981, in Saitama Prefecture. She is affiliated with the talent agency I`m Enterprise. Her career began after she enrolled in the Japan Narration Acting Institute in her final year of high school, and she made her debut as a voice actress in 1999. Her first leading role came in 2001 as the protagonist Kokoro in the anime Kokoro Library. Following this, she took a break of about a year and a half to focus on her studies before fully committing to her voice acting career.

Saitō is highly regarded for her versatility and distinctive vocal range, often bringing to life characters who are cute and humorous as well as those who are sharp-tongued, complex, or have a "dark side." Her performance as the dual-natured characters Hazuki in MoonPhase and Rebecca Miyamoto in Pani Poni Dash! were particularly noted for showcasing her ability to balance both "moe" and "black-hearted" qualities simultaneously. She has voiced numerous iconic roles over her career. Among her most famous are the cool and determined Homura Akemi in Puella Magi Madoka Magica, the sharp-tongued and "tsundere" Hitagi Senjougahara in the Monogatari series, the spirited Natsumi Hinata in Sgt. Frog, the courageous Princess Yona in Yona of the Dawn, and Aika S. Granzchesta in the Aria series.

Throughout her extensive career, she has been involved in a wide variety of genres. She has voiced characters in long-running series such as One Piece (as Chimney and Boa Sandersonia) and Gintama (as Kuriko Matsudaira). Her filmography also includes significant roles in franchise hits like Louise Halevy in Mobile Suit Gundam 00, Chloe von Einzbern in Fate/kaleid liner Prisma Illya, Francesca Lucchini in Strike Witches, Riko Aida in Kuroko`s Basketball, and Maya Yotsuba in The Irregular at Magic High School. In the world of video games, she is known for voicing Tamamo-no-Mae (Caster) in the Fate/Extra and Fate/Grand Order series, Aoi Asahina in the Danganronpa series, and Jean in Genshin Impact.

Saitō has been the recipient of an award for her work, winning the Best Supporting Voice Actress award at the Newtype×Machi★Asobi Anime Awards in 2011, the same year her character Homura Akemi won the Best Female Character award. She has a long history of collaborating with director Akiyuki Shinbo, having worked with him on series such as Puella Magi Madoka Magica, the Monogatari series, and MoonPhase, leading to her being affectionately referred to as one of his "regular" voice actors. She was also part of the voice acting units "coopee" with Natsuko Kuwatani and "MORE PEACH SUMMER SNOW" with other cast members from Sgt. Frog. In her personal life, she announced her marriage in July 2013 and gave birth to a daughter in October 2015.