Glass sponges represent a key component of benthic deep-sea communities, yet they remain rarely studied beyond mesophotic and bathyal depths. Video material collected over a decade of deep-sea expeditions revealed previously undocumented assemblages of glass sponges across a broad range of abyssal and hadal habitats in multiple ocean basins. We used a morphological approach to study these assemblages, identifying more than 3000 individuals and assigning them to over 100 morphospecies divided into 11 morphological macro-categories. Sponge abundance peaked in dives between 4000 and 5000 m. Stalked glass sponges were the most common morphology and occurred in almost all environments, followed by laminar morphologies. Erect, massive, and barrel morphologies were also present across multiple habitats, but at consistently lower abundances. Slope influenced assemblage composition: horizontal habitats supported mixed assemblages, sloped habitats were dominated by stalked morphologies, and subvertical habitats favoured funnel, barrel, and irregular morphologies. In our study, fine-grained sediment assemblages were dominated by stalked morphologies, while substrates with low-density nodules supported both laminar and stalked morphologies, and rocky substrates hosted the highest morphological diversity. These results highlight how glass sponge morphologies vary across abyssal and hadal environments, reflecting the combined influence of bathymetry, seafloor slope, and substrate type.