The St Lucia Black Finch (Melanospiza richardsoni) is a species of bird in the Thraupidae family. Sometimes classified in the bunting and American sparrow family Emberizidae, more recent studies have shown it to belong in the tanager family. It is monotypic within the genus Melanospiza. It is endemic to Saint Lucia.

Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical dry shrubland, and plantations . It is threatened by habitat loss.