Anemonastrum flaccidum, the flaccid anemone or soft windflower, is a plant species in the family Ranunculaceae.

The flowers are about 2 cm in diameter with white calyx.

The plant spreads with rhizomes, and so it often forms communities.

Anemonastrum flaccidum occurs naturally along the Amur River; in Sakhalin; in central, eastern and southern China; in Korea and in Japan.

It is found in moist places out of direct sunlight (full shade or semi-shade) and near streams and ravines in loose peaty soils.