Glionnetia is a monotypic genus of flowering plants in the Rubiaceae family. The genus contains only one species, viz. Glionnetia sericea, which is endemic to Mahé and Silhouette Island in the Seychelles. The species thrives mainly on high ridges in the mountains and it does not seem to grow well at lower altitudes. Glionnetia sericea is a small tree with paniculate terminal inflorescences and it has capsules that are dispersed by wind.