Shiho Niiyama (新山 志保, Niiyama Shiho, March 21, 1970 – February 7, 2000) was a Japanese voice actress from Matsuyama, Ehime.

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.

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.

Her final performance was in the TV series Record of Lodoss War: Chronicles of the Heroic Knight as the voice of Deedlit.