Brillantaisia is a genus of plant in family Acanthaceae. They are native to the African tropics and subtropics, including Madagascar. They may grow from 20 cm to 2 m in height. Their hirsute stems are square in cross-section and their heart-shaped leaves have an opposite arrangement. Their purple or white pea-like flowers produce long, cigar-shaped seed pods. They reproduce easily from seeds or vegetatively. One species, B. lamium, is invasive in Queensland.