Acer sieboldianum (Siebold's maple; Japanese: コハウチワカエデ, romanized: kohauchiwakaede) is a species of maple native to Japan and common in the forests of Hokkaidō, Honshū, Shikoku and Kyūshū Islands; in the south of the range it is restricted to mountain forests.

It is a slow-growing, small to medium-sized deciduous tree growing to 10–15 metres (33–49 ft) tall, with smooth grey-brown bark.

The young shoots are green to red, thinly covered with white hairs in their first year.

The young leaves in spring are downy with white hairs, with the petiole and veins on the underside of the leaf remaining hairy all summer, a feature useful in distinguishing it from the related Acer palmatum.

Flowering is in late spring, with fruit maturation in early autumn.