Shizumi Niki is a Japanese voice actress known for her work in anime, video games, and dubbed foreign films. She was born on September 20 in Nagano Prefecture, Japan, and is affiliated with the talent agency Aoni Production. She is a graduate of the Aoni Juku training school, having completed the 16th term of its Tokyo program. Her career as a voice actor began in 1996.

Niki is perhaps best known for her role as Eriko Kaneda, commonly referred to as Doc, in the cyberpunk anime series Texhnolyze from 2003. Doc is a scientist from the elite class exiled to the underground city of Lux, where she becomes a key figure advancing the series' central theme of mechanical body augmentation. Her other notable television anime roles from the same period include a small part as a noblewoman in InuYasha and as the mother of the character Shadia in the series Chrno Crusade. In the late 1990s, she appeared in major franchise installments such as Dragon Ball GT, the original Yu-Gi-Oh! series as the mother of Hiroto Honda, and Turn A Gundam.

Outside of television, her film work includes a role in the One Piece movie Clockwork Island Adventure. She has also contributed to the video game industry with performances in titles such as Growlanser and The Love Game, as well as in the visual novel series Dancing Blade. Her work extends to Japanese tokusatsu productions, where she provided the voice for the chimera creature in an episode of Mahou Sentai Magiranger in 2005. In addition to character acting, she has performed narration for Japanese television programs.