Human infrastructure development often encroaches on coastal environments, such as beaches and dunes, leading to their degradation and loss. This study presents the first global assessment of the extent to which human infrastructure squeezes beaches and dunes. We analyzed global datasets on the location of human infrastructure, including built-up areas, roads, railways, ports, and dams, in relation to the global shoreline. We found that nearly one-third (32%) of the world's sandy coastlines are squeezed by human infrastructure, with the highest levels of squeezing occurring in Europe (56%), followed by Asia (42%) and North America (37%). The squeezing of beaches and dunes is particularly severe in small island developing states, with over half (54%) of their sandy coastlines squeezed by human infrastructure. Our study highlights the need for sustainable coastal development strategies to minimize the negative impacts of human infrastructure on beaches and dunes, which are important natural buffers against coastal hazards and provide essential ecosystem services.