Saishū Onoe (尾上柴舟 Onoe Saishū?) (1876–1957) was a Japanese tanka poet and calligrapher.
Saishū wrote a poetry column for the magazine Shinsei ("New Voices"). He also founded the Shazensō Sha ("Plantain Society") in 1905, which stressed clarity, simplicity, and capturing ordinary experiences in poetry. This was in reaction to the style of the tanka poets associated with Myōjō magazine (such as Yosano Akiko) which emphasized the passionate side of human nature. Members of the Shazensō Sha included the noted Naturalist tanka poets Wakayama Bokusui and Maeda Yūgure (who had been tutored by Onoe Saishū).