Keiko Moriuchi （森内敬子）is an artist based in Japan.

Born in Osaka in 1943, she was active in Tokyo's Neo Dada group before encountering Gutai founder Jirō Yoshihara in 1962 while studying at Osaka Shoin Women's University.

She was the last artist to join Japan’s legendary Gutai Art Association in 1968 at the founder Jiro Yoshihara's personal invitation, and remained an active member until the group's dissolution in 1972, following his death. Gutai championed radical experimentation and direct engagement with materials, breaking from artistic tradition in a postwar Japan.

Yoshihara encouraged her to pursue her practice in New York rather than Paris, moving to New York in 1965, a decision that would prove transformative. Living and working in the same building as Ad Reinhardt, she developed close relationships with Isamu Noguchi, Man Ray, and Matsumi Kanemitsu.

Today at 83, Moriuchi continues the practice she has pursued for six decades: rendering cosmic structures visible through paint and gold. Gold leaf is central to her work. Applied in rich, tactile layers, it interacts dynamically with light, shifting and shimmering throughout the day and into the night. Her canvases unite cosmic patterns, mythological symbols, and mathematical principles, visual languages bridging Eastern philosophy with contemporary explorations of the fundamental order of existence.

Her work has since been featured in museum shows and major public commissions in Japan, including installations at Kawanishi Town Hall in Nara Prefecture and Kakegawa Station in Shizuoka Prefecture.