To satisfy the increasing global demand for agricultural products, the expansion of irrigation is an important intensification measure. At the same time, unsustainable water ions and cropland expansion pose a threat to biodiversity and ecosystem functioning. Irrigation potentials are influenced by local biophysical irrigation water availability and competition of different water users. Using a novel hydro‐economic data processing routine that considers economic criteria of water allocation via a productivity ranking of grid cells and both land and water sustainability criteria, we estimate global irrigation potentials at a 0.5° spatial resolution. We show that there is considerable technical potential to expand irrigation within local water and land boundaries. In terms of potentially irrigated areas on all global land suitable for crop production, 2,144 Mha could be irrigated within land and water environmental boundaries when only considering biophysical criteria. However, not all of these areas would actually be irrigated under consideration of irrigation costs. Of these, only 698 Mha (330 Mha) have a yield gain of more than 300 (600) USD ha−1 under the current crop mix valued at their current commodity price (economic irrigation potential). Plain Language Summary Irrigation plays an important role in food production. Global crop demand is expected to increase due to the growing world population and increasing role of bioenergy to mitigate climate change. Irrigation can contribute to meeting this increasing demand by facilitating higher crop yields per hectare of agricultural land, but also has environmental consequences. In this study, we quantify the areas across the globe that can be irrigated given economic and environmental constraints. We determine how much area and which areas can be irrigated globally given local water availability; how much of these can be irrigated while protecting water flows and land for biodiversity conservation; as well as the economic benefit of irrigation in different locations. We find that 2,144 Mha could be irrigated globally while respecting land and water environmental boundaries when only considering biophysical constraints. In reality, many of these areas might not be irrigated for economic reasons. Where the gain through irrigation is small, farmers might not install irrigation equipment. According to our estimation, only 698 Mha (362 Mha) have yield gains of at least 300 (600) USD ha−1. Key Points Our data processing routine provides a hydrological input aggregation tool to global land‐system models We find considerable global potential to expand irrigation within local environmental (land and water) limits Of the 2,144 Mha that could technically be irrigated, only 698 (330) Mha have a yield gain of at least 300 (600) USD ha−1