Saya Aizawa is a Japanese voice actress born on September 9, 1999, in Saitama Prefecture, Japan. Her interest in the voice acting profession began during her sixth-grade year after watching the anime series Bakemonogatari. Inspired by this, she pursued a career in the industry and successfully applied to the voice acting division of the agency Stardust Promotion, passing the final round of auditions on January 1, 2016. She was part of the agency's voice actor unit SoundOrion from 2017 until her graduation from the group in May 2019. After a period of health-related hiatus starting in December 2023, she gradually resumed her activities in early 2024. In 2025, she transitioned to working as a freelance voice actress.

Aizawa has built a diverse portfolio of roles in both anime television series and video games. In anime, some of her well-known performances include Kisara in Engage Kiss, Kagetsu in In the Heart of Kunoichi Tsubaki, Kozakura Konno in Chidori RSC, Norn Greyrat in Mushoku Tensei: Jobless Reincarnation, Shizuri Castiella Kasugaya in the Strike The Blood series, Sherry Barnett in The Eminence in Shadow, Karen Inukai in My Life as Inukai-san's Dog, Yuzuki Tachibana in Taisho Otome Fairy Tale, Chiharu Andō in Chio's School Road, and Hiromi Seki in THE IDOLM@STER Cinderella Girls Theater. She is also set to voice the lead role of Monica Everett in the anime adaptation of Silent Witch. Her work extends significantly into video games, where she is known for roles such as Mejiro Ardan in Uma Musume Pretty Derby, Charlotta Skopovskaya in Heaven Burns Red, and Pompeo Magno in Azur Lane.

Throughout her career, Aizawa has been involved in recurring projects and collaborations. Her long-standing role as Hiromi Seki in the extensive THE IDOLM@STER Cinderella Girls franchise is a notable example of a character she has voiced across multiple anime shorts, games, and live events. Similarly, her portrayal of Norn Greyrat has spanned multiple parts and seasons of the Mushoku Tensei anime adaptation. In addition to her anime and game work, she has participated in stage productions, radio programs, and served as a tourism ambassador for the Onsen Musume project. Her hobbies include sleeping and visiting model homes, and she holds several certifications, including in information processing and as an onsen (hot spring) sommelier.