Rhododendron indicum is an azalea Rhododendron species native to Japan (S & W Honshu, Shikoku, Kyushu, Yakushima).
It is the type species for the Tsutsusi section and subsection, and was the original Tsutsusi described by Engelbert Kaempfer in Japan in 1712, from the Japanese name Kirishima-tsutsuji.
There are many cultivars, including the Satsuki azaleas.