Viola helenae is a rare species of flowering plant in the violet family known by the common name Wahiawa stream violet. It is endemic to Hawaii, where it is known only from the Wahiawa Mountains of Kauai. It is threatened by exotic plant species and feral pigs. It is a federally listed endangered species of the United States. This plant is a subshrub which can reach 8 meters in height. It has long, narrow leaves and pale purple or white flowers.