Phalaenopsis mentawaiensis is a species of orchid endemic to Sumatra, Indonesia.

[1] The specific epithet mentawaiensis refers to the Mentawai islands of West Sumatra.

This species is a small-sized, hot-growing epiphyte with 15–50 cm long, inclined to erect, branched or unbranched inflorescences.

They produce slightly fragrant flowers of similar floral fragrance to Phalaenopsis violacea.

[3] This species occurs on tall trees in elevations of 0–100 m above sea level.