Rei Matsuzaki is a Japanese voice actress born on May 31, 1985, in Fukuoka Prefecture. She is affiliated with the talent agency Mausu Promotion. Matsuzaki graduated from the Japan Narration Acting Institute and made her debut as a voice actress in 2007 after passing the Aniplex Super Voice Audition.

Her career includes a wide range of roles in anime, video games, and OVAs. One of her most prominent and recurring roles is Kirari Moroboshi in the multimedia franchise The IDOLM@STER Cinderella Girls, appearing in both the main anime series and its spin-off, The IDOLM@STER Cinderella Girls Theater. She has also taken over legacy roles, notably voicing Jam Kuradoberi in the Guilty Gear series starting in 2015, a character previously portrayed by Manami Komori, whom Matsuzaki cited as a major inspiration for her career.

The following are some of her major voice roles as listed in the query:
In The Ambition of Oda Nobuna, she voices the character Niwa Nagahide. She plays Yoriko Fujiwara in Love To-LIE-Angle (also known as Tachibanakan To Lie Angle). In the series Interspecies Reviewers, her role is Eldry. Matsuzaki voices Niina in Haitai Nanafa. She plays Ayame Reikadou in My Mental Choices Are Completely Interfering With My School Romantic Comedy. Her role in Copihan is Asagi Tsugayama. In the OVA Mahō Sensei Negima!: Mō Hitotsu no Sekai - Extra Mahō Shōjo Yue, she voices the character J. von Katze. She also voices Miso in the series Nya-men.

In addition to these, Matsuzaki is known for her roles as Akino (藤堂秋乃) in Princess Connect! Re:Dive, Kanon Mizushiro in Jewelpet Sunshine, and Hishi Akebono in Umamusume: Pretty Derby. She has also appeared in numerous other anime such as Fate/Zero, Naruto, and Puella Magi Madoka Magica. Her video game work extends to titles like Fire Emblem: Awakening, Street Fighter V, and Street Fighter 6, where she voices the character Li-Fen.

Matsuzaki is known to be an avid fan of the Tokyo Yakult Swallows baseball team. This interest led her to co-host a baseball-related radio program, Rei & Yui no Bunkahōsō Home Run Radio!, with fellow voice actress Yui Watanabe.