Australia has diverse landscapes ranging from wet tropical regions in the North to temperate regions in the South and a vast arid interior. This variety has given rise to not only a speciose bat fauna, but also a variety of wetland ecosystems. The relationship between bats and wetlands is influenced by a range of environmental gradients including: aridity and climate variability, hydrological, structural, productivity and salinity. However, little is known about how these gradients influence bats in Australian wetland systems. Our aim was to determine whether wetlands were important for Australia’s bat communities, identify the environmental gradients influencing this importance, and review the threats to wetland bat communities combining a review and meta-analysis. We reviewed the literature on bats within wetland ecosystems in six ecoregions (arid, semi-arid floodplain, temperate, tropics, estuarine/saline and urban) in Australia. We used a meta-analysis to estimate relative wetland importance across ecoregions by calculating the effect size of the difference in bat activity between 43 paired wet and dry habitats. Bats were significantly more active in wet than surrounding dry habitats in arid and semi-arid floodplain. Urban wetlands also hosted greater bat activity than surrounding dry areas in 4 out of 7 sites. Wetlands were generally less important for bats in warm, wet tropical areas, and more important for bats in dry landscapes where landscape woody cover and productivity were low. Relative to dry areas within each region assessed, wetlands were most important for bats in semi-arid floodplain and urban regions. These regions are also under greatest threats from vegetation clearing, modification of flow regimes, development pressures, pollution and climate change.