Trillium kurabayashii is a species of flowering plant in the bunchflower family Melanthiaceae. The species is endemic to the western United States, occurring in extreme southwestern Oregon, northwestern California, and the Sierra Nevada of northern California. It was first described by John Daniel Freeman in 1975. The specific epithet kurabayashii honors Masataka Kurabayashi, a Japanese cytologist and population geneticist who first postulated the taxon’s existence. It is commonly known as the giant purple wakerobin, a reference to its conspicuously large, dark purple-red flower, one of the largest of any sessile-flowered trillium.

Unlike most other authorities, the influential Jepson Manual does not recognize Trillium kurabayashii as a distinct species. This discrepancy has led to widespread confusion regarding the identification and distribution of other purple-flowered trilliums native to California, namely Trillium angustipetalum and Trillium chloropetalum.

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