A simple, green, one-pot mechanosynthesis method for preparing perfectly ordered mesoporous carbons (OMCs) by ball-milling is presented herein. Mimosa tannin (T) and Pluronic® F127 (P) are used as the carbon precursor and as the mesopore-directing agent, respectively. Water (W) is used to promote micelle formation and also the interaction between T and P; no crosslinker is used and drying or curing steps before carbonization are not needed either. The experimental conditions, such as the milling time, the pH of added W and the P : W ratio are optimized to obtain perfect 2D hexagonal OMCs with BET areas as high as 588 m2 g−1 after carbonization at 900 °C. Carbonization temperatures up to 1500 °C or activation allow further increasing the surface area, up to ∼1900 m2 g−1, while maintaining the ordered mesoporous structure. These materials should find relevant applications in environmental remediation strategies for oil spills, in selective CO2 adsorption from humid gases or as electrodes of supercapacitors.