is a species of flowering plant in the family Hydrangeaceae that is endemic to Iriomote in the Yaeyama Islands, Okinawa Prefecture, Japan.
The species was first described by Japanese botanist Jisaburà  à Âi in 1938.
Deutzia yaeyamensis is a deciduous shrub that grows to a height of approximately , or to as high as . The oval to ovate leaves are finely serrated, while the ovoid winter buds open into clusters of some five to ten flowers, with white petals and dark yellow anthers.
Deutzia yaeyamensis is endemic to Iriomote in the Ryà «kyà « Islands, where it may be found growing in sunny spots on the cliffs that flank the island's rivers.
Deutzia yaeyamensis is classed as Endangered on the IUCN Red List and Ministry of the Environment Red List. The species has been designated a National Endangered Species under the 1992 Act on Conservation of Endangered Species of Wild Fauna and Flora, and its collection and/or relocation are prohibited.