Haruhi Nanao is a Japanese voice actress and singer born in Tokyo on February 11, 1973. She is a graduate of Seijo University, where she studied in the Faculty of Literature with a specialization in Mass Communication. Following her university education, she trained at the Bungakuza Acting Research Institute. She began her professional career under the stage name Haruhi Terada, which she used until 2014 when she changed her surname to Nanao, her mother's maiden name. She is currently affiliated with the agency 81 Produce.

Nanao has built a career as a versatile performer since debuting in the 1990s, contributing voice work to a wide array of anime television series, theatrical films, video games, and Japanese dubs of foreign live-action and animated productions. Her reputation is built on a dynamic vocal range that allows her to portray both lively, comedic characters and more heartfelt, serious roles. Beyond voice acting, she is also known for her work as a singer, having performed character songs and theme music, as well as her presence as a host and commentator on radio and television programs.

Her extensive filmography includes several prominent and long-running anime series. One of her most recognized roles is Mai Kujaku in Yu-Gi-Oh! Duel Monsters. She is also well-known as the second voice of Midori Yoshinaga, a beloved character in the long-running series Crayon Shin-chan. In the world of Digimon, she has voiced multiple characters across the franchise, including Pumpkinmon in Digimon Adventure, Ai in Digimon Tamers, Ranamon and Calmaramon in Digimon Frontier, and Piyomon in Digimon Savers. For fans of Naruto Shippuden, she provided the voice for the character Rin Nohara. She also had a role in the 2001 version of Fruits Basket as Kana Sohma.

Nanao's career also features significant roles in popular franchises. She voices the character Sella in the Fate franchise, appearing in series such as Fate/kaleid liner Prisma Illya and Fate/stay night: Unlimited Blade Works. She has a long-standing association with the Tenchi Muyo! franchise, voicing Ayeka Masaki Jurai in Ai Tenchi Muyo!. In the fantasy series Plunderer, she voiced the character Avsayette Vremya. Her work also extends to magical girl genres; besides the example of Queen Nehellenia in the Pretty Guardian Sailor Moon Eternal theatrical films, she played Hikaru Kujo and Nonomiya in Futari wa Pretty Cure Max Heart and Camellia in Fushigiboshi no Futagohime.

A significant portion of Nanao's work is in Japanese dubbing for foreign media. She has dubbed numerous Western actors, including providing the Japanese voice for Michelle Trachtenberg's character Dawn Summers in the television series Buffy the Vampire Slayer. Her dubbing filmography includes a wide range of films, such as voicing Brittany Snow's character in Prom Night, Isla Fisher's character in The Lookout, and Missi Pyle's character in Gone Girl. She also provided the voice for the character Reg Stevens, played by Brenda Song, in Like Mike and has done voice work for animated films like The Ant Bully and Barnyard.