Hexablemma is a monotypic genus of araneomorph spiders in the family Tetrablemmidae containing the single species, Hexablemma cataphractum. It was first described by Lucien Berland in 1920 from a female found in Kenya. It was separated from Tetrablemma in 1978 for this single species, because it does not belong there, but does not seem to belong anywhere else either.