Mami Deguchi is a Japanese voice actress born on December 18, 1985, in Mie Prefecture, Japan. She has A-type blood.

Her most recognized voice role is Madoka Kugimiya in the Mahou Sensei Negima! anime franchise. She provided the voice for this character across multiple installments of the series, including the original television anime, the OAD releases Shiroki Tsubasa Ala Alba and Mō Hitotsu no Sekai, and the 2011 animated film Mahō Sensei Negima! Anime Final.

In addition to her voice work, Deguchi also performed as a singer for the franchise, contributing to the song Happy☆Material, which was used as an opening theme for the television anime.