| Shiho Niiyama | |
| Native Name: | 新山 志保 |
| Native Name Lang: | ja |
| Birth Date: | 21 March 1970 |
| Birth Place: | Matsuyama, Ehime, Japan |
| Death Place: | Shinjuku, Tokyo, Japan |
| Occupation: | Voice actress |
| Years Active: | 1992 - 1998 |
| Agent: | Aoni Production |
| Height: | 163.5 cm |
was a Japanese voice actress from Matsuyama, Ehime. She was attached to Aoni Production at the time of her death. Niiyama was most known for the roles of Kou Seiya/Sailor Star Fighter in the Pretty Soldier Sailor Moon series, Risa Kanzaki in Neighborhood Story, Suou Takamura in Clamp School Detectives and Deedlit in Record of Lodoss War: Chronicles of the Heroic Knight. She was also involved in one voice actor group, Virgo, who are the voice actresses of the anime and game, Ojōsama Sōsamō.
Niiyama was diagnosed with leukemia in 1998 and later returned for a bone marrow transplant on February 7, 2000. At approximately 6:23 A.M., Niiyama suffered a bout of internal bleeding in her lung and died as a result of complications from leukemia. Niiyama was 29 years old at the time of her death. Her final performance was in the TV series Record of Lodoss War: Chronicles of the Heroic Knight as the voice of Deedlit.