Nao Yamauchi is a Japanese voice actress from Tokyo, born on May 4th. She is affiliated with the talent agency Vi-vo. Her hobbies include reading, playing the piano, and volleyball.

Yamauchi is known for her role as Sakamoto-san in the 2004 anime television series Kappa no Kaikata. This fantasy comedy series, based on a manga by Yūgo Ishikawa, follows a young man who purchases a kappa as a pet and the challenges that ensue. In addition to this anime role, her work includes voicing the character Irui, also known as Irui Gan Eden, in the video games Super Robot Wars Alpha 2 from 2003 and Super Robot Wars Alpha 3 from 2005. She also provided the Japanese voice for the character Trixie in the anime Oops! Fairy Parents in 2001.

Her other credits include minor roles in several television anime series. She voiced a delinquent character in episode nine of Black Blood Brothers, a boy in episode twenty-six of Fairy Musketeers, a boy in episode six of Romeo x Juliet, and a schoolgirl in episode 118 of Sgt. Frog.